I think we have to use Pythagorean Therom here a² + b² = c² First we need to know the height of the Triangle (which is YT) Let "b" be the height YT: 22² + b² = 77² 484 + b² = 5929 b² = 5929 - 484 = 5445 √b² = √(5445) b = √5445 = 73.79ft Now that we have the height lets find the missing base(YK): We are going to use the same formula, but this time to find the base and with a different triangle. a² + 73.79² = 87.5² a² + 5444.96 = 7656.25 a² = 7656.25 - 5444.96 a² = 2211.29 √a² = √(2211.29) a = √2211.29 = 47.02 Now we can add the bases together to find x. Bases "VY" and "YK" x = 22+47 x = 69