I do not know I will tell u but I think it is 65?
6×6=36. also get a calculator
Add all of the sides together which then equal 76. So it would simplify to 14x+20=76. Then 14x=56. And 56/14=4. X=4
A perfect cube is a natural number in the form

therefore

and also you can define it as any natural number who's third root is also a natural number for examble
![\sqrt[3]{1000} = 10](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7B1000%7D%20%20%3D%2010)
so you can say that the tenth perfect cube is 1000