1. Table of Contents 31. Finding Missing Angles

2. Finding missing angles
Std – MM2G2 Define and apply trig ratios to right triangles
Essential Question – How do you find a missing angle given 2 sides of a triangle?

3. Finding a missing angle
To find an angle measure:
If sinA=x, then A= sin-1(x)
If cosA=x, then A=cos-1(x)
If tanA=x, then A=tan-1(x)
These are called inverse trig functions

4. Finding a missing angle
These can be found on your calculator above the sin, cos, and tan keys
For sin-1, press 2nd sin
For cos-1, press 2nd cos
For tan-1, press 2nd tan

5. Ex: Find the measure of the .
sin A=.5
tan B=.1051
A=sin-1.5
A=30o
B=tan
cos A=.7071
B=6o
A=cos
A=45o

6. Steps to find missing angle in triangle
Label the two sides you are given based on angle you want to find
Figure out which trig ratio to use
Use inverse trig functions to calculate
Round to one decimal place

7. Example Find angle A
A=sin-1.96
A=74o A 25 __ __ B C 24

8. Ex: Find angle A C __ __ 10 8 B A
A=51.3o
A= tan-11.25

9. Example S 15 __ __ T R 7
Find ms

10. Example solve for x 15.7mi __ x __ 59mi tan x=.2661 x= tan-1.2661
x=14.9o