The given triangle is a right angle triangle. We would find x by applying the pythagorean theorem which is expressed as
hypotenuse^2 = one leg^2 + other leg ^2
Looking at the triangle,
hypotenuse = 15
one leg = x
other leg = 8
Thus,
15^2 = x^2 + 8^2
225 = x^2 + 64
x^2 = 225 - 64 = 161
T