Find the diagonal of a cube if its side equals 5.

Question

dumbcow · Answer

$$=\sqrt{5^{2}+ (5\sqrt{2})^{2}}=\sqrt{125}=5\sqrt{5}$$

anonymous · Answer

i think you're wrong dumbcow :) ?(

if a side is 5 on the square, then you can use a² + b² = c²

which would be 5² + 5² = 50 or sqrt(50) is your answer... because squares' internal angles are made of 90 degrees each... so you can use that Pythagorean formula

dumbcow · Answer

@paul you are correct for finding diagonal for square
sqrt(50) = 5sqrt(2)
diagonal of cube is from corner to corner
this triangle has legs of 5 and 5sqrt(2)

anonymous · Answer

oh yeah... question said cube... sorry