### Home > PC > Chapter 7 > Lesson 7.3.2 > Problem 7-113

7-113.

Given

Draw a reference triangle in Quadrant 1 for both angles.

Label the 3rd side.

Both are pythagorean triples:and Find sin

*A*from the triangle sides.

Find

from the triangle sides.

Use the sum and difference formula:

sin(*A*+*B*) = sin*A*cos*B*+ cos*A*sin*B*

Use the sum and difference formula: