The "Law of Tangents" can be used to calculate the angles or sides of a triangle.
Law of Tangents
The "Law of Tangents" can be expressed as
(a + b) / (a - b) = tan 1/2 (A + B) / tan 1/2 (A - B) (1)
a, b and c = length of sides in triangle (m, ft ...)
A, B and C = angles in the triangle (degrees)
The Pythagorean theorem can be expressed as
a2 + b2 = c2 (2)
Law of sines
The Law of sines can be expressed as
a / sin(A) = b / sin(B) = c / sin(C) (3)
If the length of all three sides in the triangle are known - the angles can be calculated as
A = arccos((b2 + c2 - a2) / (2 b c)) (4a)
B = arccos((a2 + c2 - b2) / (2 a c)) (4b)
C = arccos((a2 + b2 - c2) / (2 a b)) (4c)
Mathematical rules and laws - numbers, areas, volumes, exponents, trigonometric functions and more.
Calculate angles with a straight board across carpenter's square.
One side of a triangle when the opposite angle and two sides are known.
Calculate the angles in a generic triangle.
Calculate miter saw protractor angles for skirting and decorative mouldings work.
Calculate oblique triangles.
Verifying square corners.
Right angled triangle equations.
A rectangle is square if the lengths of both diagonals are equal.
Triangle analytical geometry.
Sine, cosine and tangent - the natural trigonometric functions.