1. By Amber Wolfe and Savannah Guenther

2. Introduction

3. Equation Use the equation below for non-right triangles given (side-angle-side) or (side-side-side) to solve for either an angle or a side.

4. Example 1 Solving a triangle (SAS) Given ABC, a=11, b=5, C=20 c 2 = a 2 + b 2 – 2ab cos C = 11 2 + 5 2 -2(11)(5) cos(20) = 42.634... c = √42.634... = 6.5 A 11 20 5 CB

5. Example 2 Solving a triangle (SSS) Given ABC, a=9, b=7, c=5 a 2 = b 2 + c 2 – 2bc cos A 9 2 + 7 2 -2(7)(5) cos A 70 cos A = -7 A = cos -1 (-0.1) = 95.7 b 2 = a 2 + c 2 – 2ac cos B 7 2 = 9 2 + 5 2 – 2(9)(5) cos B 90 cos B = 57 B = cos -1 (57/90) = 50.7 Then C = 180 – 95.7 – 50.7 = 33.6 A 57 9 CB

6. References www.mathbook.com www.dudelol.com www.paworldmathclass.web.com Precalculus math book Test #4 Practice Quiz