The third angle is 105. How do I know this? Add 22 and 53: 22 + 53 = 75 All interior angles on a triangle should add up to 180. Subtract 75 from 180: 180 - 75 = 105 105 is our answer. Hope this helps! =)
You need the formula for geometric mean for right triangles as it applies to the altitude. For us, that formula will be where BD is your altitude. The formula then, filled in accordingly, would be . We cross multiply to get that . Divide both sides by 4 to get , so x = 5. Choice C is the one you want.