Explanation:
Pythagoras
c² = a² + b²
c being the Hypotenuse (the line opposite of the 90° angle) of the right-angled triangle.
9² = 5² + side²
81 = 25 + side²
56 = side²
side = sqrt(56) = sqrt(4×14) = 2×sqrt(14)
1.6m questions
2.0m answers