Trigonometry, abbreviated as TRIG, is a branch of mathematics that deals with the relations between the sides and angles of plane or spherical triangles.

Trigonometry Glossary

• 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

A

• Arccosine  -  arccos, the inverse cosine.

• Arccotangent  -  arccot , the inverse cotangent.

• Arccosecant  -  arccsc, the inverse cosecant.

• Arcsecant  -  arcsec , the inverse secant.

• Arcsine  -  arcsin , the inverse sine.

• Arctangent  -  arctan , the inverse tangent.

C

• Cosecant  -  csc, 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, the ratio of the adjacent side to the oposite in a right triangle.

D

E

F

G

H

• Heron's formula   -   A formula for the area of a triangle when the lengths of the three sides are known.

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

I

• Infinite  -  Having no boundary.

• Inverse statement   -   Disaliow both the hypohesis and conclusion of the origional statement.

J

K

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.

M

N

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.

Q

R

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

S

• Secant  -  sec, the ratio of the hypotenuse to the side adjacent to a given angle in a right triangle.

• Sine  -  sin, the ratio of the length of the opposite side to the length of the hypotenuse.

T

• Tangent  -  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

U

V

W

X

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

Y

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

Z

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