1. 8.3 Ratios in Right Triangles
To find trig ratios using right triangles
To solve problems using trig ratios

2. Background
trigonometry- the word comes from 2 Greek words trigon-meaning triangle
metron meaning measure.
hypotenuse A B C
Adjacent
opposite
A ratio of the lengths of sides of a right triangle .

3. Watch this video...

4. OS AN IN pposi te djacent pposi te djacent SOH CAH TOA ypotenuse
What to remember

5. Example
Find sin A, cos A, tan A, sin B, cos B, and tan B. Express each ratio as a fraction and as a decimal B 13 5 A C 12

6. Example
Find the value of each ratio to the nearest ten-thousandth
sin 7o
= .1219
cos 30o
= .8660
Example
Find the measure of each angle to the nearest tenth degree
tan C =
sin A = .7245
A = sin
C = 84o
A = 46.4o

7. Example
Find x
determine the relationship between the given angle and the sides x
63o
cross multiply
solve for x 20
.891x = 20
x = 22.45

8. Homework
Put this in your agenda
Pg odd,