Trigonometry, abbreviated as TRIG, is a branch of mathematics that
- Arccos - The inverse cosine.
- Arccot - The inverse cotangent.
- Arccsc - The inverse cosecant.
- Arcsec - The inverse secant.
- Arcsin - The inverse sine.
- Arctan - The inverse tangent.
- Cosecant - The ratio of the hypotenuse over opposite side in a right triangle.
- Cosine or cos - The ratio of the adjacent side of the hypotenuse in a right triangle.
- Cotangent - The ratio of the adjacent side to the oposite in a right triangle.
- Hero's formula -
- Heron's formula -
- Hyporenuse - The side of right triangle opposite the right angle, which is the longest side.
- Infinite - Having no boundary.
- Law of cosines - An equation relating to cosine of an interior angle and the lengths of the sides of a triangle.
- Law of sines - The ratio of the sine of any angle within any specific triangle and the length for the opposite side is a constant.
- Orthocenter - The point of concurrence of the altitudes of the triangle.
- Orthogonal - Perpendicular to a plane.
- Pythagorean theorem - An equation relating the lengths of the sides of a right triangle. The sum of the squares of the legs of a right triangle is equal to the square of the hypotenuse.
- Proportional - In a constant ratio.
- Ratio - A constant proportion or two real numbers divided by each other.
- Sine or sin - The ratio of the length of the opposite side to the length of the hypotenuse.
- Tangent or tan - The ratio of the opposite side to the adjacent side of a right triangle.
- Tangent line - A line that touches the graph of the function at a single point.
- X-axis - The horizontal axis on a coordinate system.
- Y-axis - The vertical axis on a coordinate system.