Answer: X=8
Explanation:
Since a triangle is 180 degrees in measure, you would first have to set up an equation. The equation would be 71+45+8x=180.
Then you add the like terms, 71 and 45, which equals 116. Then, your equation would look like this: 116+8x=180. Thus, you subtract 116 from both sides, resulting in 8x=64. After you divide by 8 on both sides x=8.