## Trigonometry

Trigonometry, abbreviated as TRIG, is a branch of mathematics that deals with the relations between the sides and angles of plane or spherical triangles. For other math terms see Algebra and Geometry.

### Math Symbols

- Algebra symbols / Angle and Line symbols / Basic Math symbols / Bracket symbols / Equivalence symbols / Geometry symbols / Greek alphabet / Roman numerals

### Nomenclature & Symbols for Engineering, Mathematics, & Science

- A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z

## Trigonometry Terms

### A

- Arccos - The inverse cosine.

- Arccot - The inverse cotangent.

- Arccsc - The inverse cosecant.

- Arcsec - The inverse secant.

- Arcsin - The inverse sine.

- Arctan - The inverse tangent.

### C

- Cosecant (csc, cosec) - The ratio of the hypotenuse over opposite side in a right triangle.

- Cosine (cos) - The ratio of the adjacent side of the hypotenuse in a right triangle.

- Cotangent (cot, ctg) - The ratio of the adjacent side to the oposite in a right triangle.

### H

- Hyporenuse - The side of right triangle opposite the right angle, which is the longest side.

### I

- Infinite - Having no boundary.

### L

- 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.

### O

- Orthocenter - The point of concurrence of the altitudes of the triangle.

- Orthogonal - Perpendicular to a plane.

### P

- 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.

### R

- Ratio - A constant proportion or two real numbers divided by each other.

### S

- Sine (sin) - The ratio of the length of the opposite side to the length of the hypotenuse.

### T

- Tangent (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.

- Tangent of a circle - A line that contacts an arc or circle at only one point.

- Trig functions - sine, cosine, tangent, cosecant, secant, and cotangent

### X

- X-axis - The horizontal axis on a coordinate system.

### Y

- Y-axis - The vertical axis on a coordinate system.