Answer:
x = 85
Step-by-step explanation:
Because this is a right triangle, we can use the Pythagorean Theorem:
a² + b² = c²
Where c is the hypotenuse, or the longest side. This is opposite to the right angle of the right triangle. So now you have:
84² + 13² = x²
7056 + 169 = x²
7225 = x²
√7225 = √x²
85 = x
x = 85
