LibGuides: Math Help: Find an unknown side length

FIND AN UNKNOWN SIDE LENGTH

In this module, you can study how to use trig ratios (sine, cosine and tangent) to find an unknown side length in a right triangle.

A right triangle can have its right angle at the top.

Study and practice

Using trig ratios to find the length of a side
This page explains how to choose which trig ratio (sine, cosine or tangent) to use when you need to find the length of a side.
Read about using sines to find the length of a side
Read about how to find an unknown opposite side or hypotenuse using sine ratios at teacherschoice.com.au.
Read about using cosines to find the length of a side
Read about how to find an unknown adjacent side or hypotenuse using cosine ratios as teacherschoice.com.au.
Read about using tangents to find the length of a side
Read about how to find an unknown opposite or adjacent side using tangent ratios at teacherschoice.com.au.
Quiz yourself on finding an unknown side length using trig
Do you know how to find an unknown side length using sine, cosine and tangent? Check your understanding with this online quiz at mathopolis.com