# Intro to Trig

- Author:
- ericagiatas

## Consider the Following..

How many triangles do you see? How do they relate? How do you know?

## Now use the slider D to move EF...

Since these triangles are similar, we know that the corresponding sides are in proportion. Look closely at the relationship between FE/EA and CB/BA. What happens to this relationship as you move EF?

## Predict

What do you think would happen if angle A (theta) changed?