mathlib3 documentation

geometry.euclidean.angle.oriented.right_angle

Oriented angles in right-angled triangles. #

THIS FILE IS SYNCHRONIZED WITH MATHLIB4. Any changes to this file require a corresponding PR to mathlib4.

This file proves basic geometrical results about distances and oriented angles in (possibly degenerate) right-angled triangles in real inner product spaces and Euclidean affine spaces.

An angle in a right-angled triangle expressed using arccos.

An angle in a right-angled triangle expressed using arccos.

An angle in a right-angled triangle expressed using arcsin.

An angle in a right-angled triangle expressed using arcsin.

An angle in a right-angled triangle expressed using arctan.

An angle in a right-angled triangle expressed using arctan.

theorem orientation.cos_oangle_add_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle x (x + y)).cos = x / x + y

The cosine of an angle in a right-angled triangle as a ratio of sides.

theorem orientation.cos_oangle_add_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x + y) y).cos = y / x + y

The cosine of an angle in a right-angled triangle as a ratio of sides.

theorem orientation.sin_oangle_add_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle x (x + y)).sin = y / x + y

The sine of an angle in a right-angled triangle as a ratio of sides.

theorem orientation.sin_oangle_add_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x + y) y).sin = x / x + y

The sine of an angle in a right-angled triangle as a ratio of sides.

theorem orientation.tan_oangle_add_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle x (x + y)).tan = y / x

The tangent of an angle in a right-angled triangle as a ratio of sides.

theorem orientation.tan_oangle_add_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x + y) y).tan = x / y

The tangent of an angle in a right-angled triangle as a ratio of sides.

theorem orientation.cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle x (x + y)).cos * x + y = x

The cosine of an angle in a right-angled triangle multiplied by the hypotenuse equals the adjacent side.

theorem orientation.cos_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x + y) y).cos * x + y = y

The cosine of an angle in a right-angled triangle multiplied by the hypotenuse equals the adjacent side.

theorem orientation.sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle x (x + y)).sin * x + y = y

The sine of an angle in a right-angled triangle multiplied by the hypotenuse equals the opposite side.

theorem orientation.sin_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x + y) y).sin * x + y = x

The sine of an angle in a right-angled triangle multiplied by the hypotenuse equals the opposite side.

The tangent of an angle in a right-angled triangle multiplied by the adjacent side equals the opposite side.

The tangent of an angle in a right-angled triangle multiplied by the adjacent side equals the opposite side.

theorem orientation.norm_div_cos_oangle_add_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
x / (o.oangle x (x + y)).cos = x + y

A side of a right-angled triangle divided by the cosine of the adjacent angle equals the hypotenuse.

theorem orientation.norm_div_cos_oangle_add_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
y / (o.oangle (x + y) y).cos = x + y

A side of a right-angled triangle divided by the cosine of the adjacent angle equals the hypotenuse.

theorem orientation.norm_div_sin_oangle_add_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
y / (o.oangle x (x + y)).sin = x + y

A side of a right-angled triangle divided by the sine of the opposite angle equals the hypotenuse.

theorem orientation.norm_div_sin_oangle_add_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
x / (o.oangle (x + y) y).sin = x + y

A side of a right-angled triangle divided by the sine of the opposite angle equals the hypotenuse.

A side of a right-angled triangle divided by the tangent of the opposite angle equals the adjacent side.

A side of a right-angled triangle divided by the tangent of the opposite angle equals the adjacent side.

An angle in a right-angled triangle expressed using arccos, version subtracting vectors.

An angle in a right-angled triangle expressed using arccos, version subtracting vectors.

An angle in a right-angled triangle expressed using arcsin, version subtracting vectors.

An angle in a right-angled triangle expressed using arcsin, version subtracting vectors.

An angle in a right-angled triangle expressed using arctan, version subtracting vectors.

An angle in a right-angled triangle expressed using arctan, version subtracting vectors.

theorem orientation.cos_oangle_sub_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle y (y - x)).cos = y / y - x

The cosine of an angle in a right-angled triangle as a ratio of sides, version subtracting vectors.

theorem orientation.cos_oangle_sub_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x - y) x).cos = x / x - y

The cosine of an angle in a right-angled triangle as a ratio of sides, version subtracting vectors.

theorem orientation.sin_oangle_sub_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle y (y - x)).sin = x / y - x

The sine of an angle in a right-angled triangle as a ratio of sides, version subtracting vectors.

theorem orientation.sin_oangle_sub_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x - y) x).sin = y / x - y

The sine of an angle in a right-angled triangle as a ratio of sides, version subtracting vectors.

theorem orientation.tan_oangle_sub_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle y (y - x)).tan = x / y

The tangent of an angle in a right-angled triangle as a ratio of sides, version subtracting vectors.

theorem orientation.tan_oangle_sub_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x - y) x).tan = y / x

The tangent of an angle in a right-angled triangle as a ratio of sides, version subtracting vectors.

theorem orientation.cos_oangle_sub_right_mul_norm_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle y (y - x)).cos * y - x = y

The cosine of an angle in a right-angled triangle multiplied by the hypotenuse equals the adjacent side, version subtracting vectors.

theorem orientation.cos_oangle_sub_left_mul_norm_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x - y) x).cos * x - y = x

The cosine of an angle in a right-angled triangle multiplied by the hypotenuse equals the adjacent side, version subtracting vectors.

theorem orientation.sin_oangle_sub_right_mul_norm_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle y (y - x)).sin * y - x = x

The sine of an angle in a right-angled triangle multiplied by the hypotenuse equals the opposite side, version subtracting vectors.

theorem orientation.sin_oangle_sub_left_mul_norm_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
(o.oangle (x - y) x).sin * x - y = y

The sine of an angle in a right-angled triangle multiplied by the hypotenuse equals the opposite side, version subtracting vectors.

The tangent of an angle in a right-angled triangle multiplied by the adjacent side equals the opposite side, version subtracting vectors.

The tangent of an angle in a right-angled triangle multiplied by the adjacent side equals the opposite side, version subtracting vectors.

theorem orientation.norm_div_cos_oangle_sub_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
y / (o.oangle y (y - x)).cos = y - x

A side of a right-angled triangle divided by the cosine of the adjacent angle equals the hypotenuse, version subtracting vectors.

theorem orientation.norm_div_cos_oangle_sub_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
x / (o.oangle (x - y) x).cos = x - y

A side of a right-angled triangle divided by the cosine of the adjacent angle equals the hypotenuse, version subtracting vectors.

theorem orientation.norm_div_sin_oangle_sub_right_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
x / (o.oangle y (y - x)).sin = y - x

A side of a right-angled triangle divided by the sine of the opposite angle equals the hypotenuse, version subtracting vectors.

theorem orientation.norm_div_sin_oangle_sub_left_of_oangle_eq_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x y : V} (h : o.oangle x y = (real.pi / 2)) :
y / (o.oangle (x - y) x).sin = x - y

A side of a right-angled triangle divided by the sine of the opposite angle equals the hypotenuse, version subtracting vectors.

A side of a right-angled triangle divided by the tangent of the opposite angle equals the adjacent side, version subtracting vectors.

A side of a right-angled triangle divided by the tangent of the opposite angle equals the adjacent side, version subtracting vectors.

theorem orientation.oangle_add_right_smul_rotation_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x : V} (h : x 0) (r : ) :

An angle in a right-angled triangle expressed using arctan, where one side is a multiple of a rotation of another by π / 2.

theorem orientation.oangle_add_left_smul_rotation_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x : V} (h : x 0) (r : ) :

An angle in a right-angled triangle expressed using arctan, where one side is a multiple of a rotation of another by π / 2.

theorem orientation.tan_oangle_add_right_smul_rotation_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x : V} (h : x 0) (r : ) :
(o.oangle x (x + r (o.rotation (real.pi / 2)) x)).tan = r

The tangent of an angle in a right-angled triangle, where one side is a multiple of a rotation of another by π / 2.

theorem orientation.tan_oangle_add_left_smul_rotation_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x : V} (h : x 0) (r : ) :
(o.oangle (x + r (o.rotation (real.pi / 2)) x) (r (o.rotation (real.pi / 2)) x)).tan = r⁻¹

The tangent of an angle in a right-angled triangle, where one side is a multiple of a rotation of another by π / 2.

theorem orientation.oangle_sub_right_smul_rotation_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x : V} (h : x 0) (r : ) :

An angle in a right-angled triangle expressed using arctan, where one side is a multiple of a rotation of another by π / 2, version subtracting vectors.

theorem orientation.oangle_sub_left_smul_rotation_pi_div_two {V : Type u_1} [normed_add_comm_group V] [inner_product_space V] [hd2 : fact (fdim V = 2)] (o : orientation V (fin 2)) {x : V} (h : x 0) (r : ) :

An angle in a right-angled triangle expressed using arctan, where one side is a multiple of a rotation of another by π / 2, version subtracting vectors.

An angle in a right-angled triangle expressed using arccos.

An angle in a right-angled triangle expressed using arccos.

An angle in a right-angled triangle expressed using arcsin.

An angle in a right-angled triangle expressed using arcsin.

An angle in a right-angled triangle expressed using arctan.

An angle in a right-angled triangle expressed using arctan.

theorem euclidean_geometry.cos_oangle_right_of_oangle_eq_pi_div_two {V : Type u_1} {P : Type u_2} [normed_add_comm_group V] [inner_product_space V] [metric_space P] [normed_add_torsor V P] [hd2 : fact (fdim V = 2)] [module.oriented V (fin 2)] {p₁ p₂ p₃ : P} (h : euclidean_geometry.oangle p₁ p₂ p₃ = (real.pi / 2)) :
(euclidean_geometry.oangle p₂ p₃ p₁).cos = has_dist.dist p₃ p₂ / has_dist.dist p₁ p₃

The cosine of an angle in a right-angled triangle as a ratio of sides.

theorem euclidean_geometry.cos_oangle_left_of_oangle_eq_pi_div_two {V : Type u_1} {P : Type u_2} [normed_add_comm_group V] [inner_product_space V] [metric_space P] [normed_add_torsor V P] [hd2 : fact (fdim V = 2)] [module.oriented V (fin 2)] {p₁ p₂ p₃ : P} (h : euclidean_geometry.oangle p₁ p₂ p₃ = (real.pi / 2)) :
(euclidean_geometry.oangle p₃ p₁ p₂).cos = has_dist.dist p₁ p₂ / has_dist.dist p₁ p₃

The cosine of an angle in a right-angled triangle as a ratio of sides.

theorem euclidean_geometry.sin_oangle_right_of_oangle_eq_pi_div_two {V : Type u_1} {P : Type u_2} [normed_add_comm_group V] [inner_product_space V] [metric_space P] [normed_add_torsor V P] [hd2 : fact (fdim V = 2)] [module.oriented V (fin 2)] {p₁ p₂ p₃ : P} (h : euclidean_geometry.oangle p₁ p₂ p₃ = (real.pi / 2)) :
(euclidean_geometry.oangle p₂ p₃ p₁).sin = has_dist.dist p₁ p₂ / has_dist.dist p₁ p₃

The sine of an angle in a right-angled triangle as a ratio of sides.

theorem euclidean_geometry.sin_oangle_left_of_oangle_eq_pi_div_two {V : Type u_1} {P : Type u_2} [normed_add_comm_group V] [inner_product_space V] [metric_space P] [normed_add_torsor V P] [hd2 : fact (fdim V = 2)] [module.oriented V (fin 2)] {p₁ p₂ p₃ : P} (h : euclidean_geometry.oangle p₁ p₂ p₃ = (real.pi / 2)) :
(euclidean_geometry.oangle p₃ p₁ p₂).sin = has_dist.dist p₃ p₂ / has_dist.dist p₁ p₃

The sine of an angle in a right-angled triangle as a ratio of sides.

theorem euclidean_geometry.tan_oangle_right_of_oangle_eq_pi_div_two {V : Type u_1} {P : Type u_2} [normed_add_comm_group V] [inner_product_space V] [metric_space P] [normed_add_torsor V P] [hd2 : fact (fdim V = 2)] [module.oriented V (fin 2)] {p₁ p₂ p₃ : P} (h : euclidean_geometry.oangle p₁ p₂ p₃ = (real.pi / 2)) :
(euclidean_geometry.oangle p₂ p₃ p₁).tan = has_dist.dist p₁ p₂ / has_dist.dist p₃ p₂

The tangent of an angle in a right-angled triangle as a ratio of sides.

theorem euclidean_geometry.tan_oangle_left_of_oangle_eq_pi_div_two {V : Type u_1} {P : Type u_2} [normed_add_comm_group V] [inner_product_space V] [metric_space P] [normed_add_torsor V P] [hd2 : fact (fdim V = 2)] [module.oriented V (fin 2)] {p₁ p₂ p₃ : P} (h : euclidean_geometry.oangle p₁ p₂ p₃ = (real.pi / 2)) :
(euclidean_geometry.oangle p₃ p₁ p₂).tan = has_dist.dist p₃ p₂ / has_dist.dist p₁ p₂

The tangent of an angle in a right-angled triangle as a ratio of sides.

The cosine of an angle in a right-angled triangle multiplied by the hypotenuse equals the adjacent side.

The cosine of an angle in a right-angled triangle multiplied by the hypotenuse equals the adjacent side.

The sine of an angle in a right-angled triangle multiplied by the hypotenuse equals the opposite side.

The sine of an angle in a right-angled triangle multiplied by the hypotenuse equals the opposite side.

The tangent of an angle in a right-angled triangle multiplied by the adjacent side equals the opposite side.

The tangent of an angle in a right-angled triangle multiplied by the adjacent side equals the opposite side.

A side of a right-angled triangle divided by the cosine of the adjacent angle equals the hypotenuse.

A side of a right-angled triangle divided by the cosine of the adjacent angle equals the hypotenuse.

A side of a right-angled triangle divided by the sine of the opposite angle equals the hypotenuse.

A side of a right-angled triangle divided by the sine of the opposite angle equals the hypotenuse.

A side of a right-angled triangle divided by the tangent of the opposite angle equals the adjacent side.

A side of a right-angled triangle divided by the tangent of the opposite angle equals the adjacent side.