  Master the 7 pillars of school success

# Trigonometric Ratios (The Basics)

Common Core Standard: G.SRT. 6 High School Geometry
Other Trigonometric Ratios

There are 3 co-functions:

Secant is the reciprocal of cosine.
Cosecant is the reciprocal of sine.
Cotangent is the reciprocal of tangent.

Cosecant = Hypotenuse/Opposite = 1/Sine

## Transcript: Trigonometric Ratios (The Basics) ​Trigonometric ratios (The Basics) The trigonometric ratios are special measurements of a right triangle. In fact, trigon is Greek for triangle, and metric is Greek for measurement. Put these together and trigonometric means triangle measurement.

Triangles have six parts, three angles, and three sides.
Using trigonometric ratios enables you can to find any measure of a triangle if you know just two of the parts.

• The hypotenuse is always opposite the right angle.
• The adjacent side is the leg closest to the reference angle. ( Angle A )
• ​The opposite side is the leg opposite the reference angle ( Angle A )

### Trigonometric Ratios Chart

Math students use SOH CAH TOA in order to help them remember the trig functions. If you have the following information: A right angle Length of opposite leg Length of the hypotenuse Use Sine   Opposite Hypotenuse Remember using   SOH A right angle Length of adjacent leg Length of the hypotenuse Use Cosine   Adjacent Hypotenuse CAH A right angle Length of opposite leg Length of the adjacent Use Tangent   Opposite Adjacent TOA

A
C
B   Related sites for Trig Ratios

Basic Trigonometry: Sin, Cos, Tan (mathbff)    This video shows how to find sin, cos, and tan using SohCahToa

Trig Ratios Information,facts, and fun activities covering trig ratios