Answer:
70.5°
Step-by-step explanation:
22² = (20)²+(18)² - 2(20)(18) cos X
484 = 400 + 324 - 720 cos X
-240 = -720 cosx
1/3 = cos X
= X
X = 70.52877937
You left out a critical piece of information in the question.
"reaches a height of of the maximum height"
6