We can represent the base as z and the height as 2z+6. We are going to use the formula A=1/2*b*h and solve for z 180=1/2*z*(2z+6) 360=2z^2+6z 0=2z^2+6z-360 0=2(z^2+3z-180) 0=(z+15)(z-12) So z=-15 and 12 but it must be positive so then the base is equal to 12
When we plug this into 2z+6 we get 30 for the height 2(12)+6=30
This problem is just one about triangles! All of the faces of the cube are perpendicular to their adjacent faces, so the diagonal of one of the face will be a right angle with the edge of the cube. Thus, you can create a right triangle. Finally, use the Pythagorean Theorem to solve for x, the length of the side of the cube.