The edge of the cube is 15 cm find 1) the sum of the lengths of all the edges of the cube 2) surface area

To solve this problem, remember that a cube is a rectangular parallelepiped, all the faces of which are squares. All the edges of a cube are equal. Proceeding from this, a1 = a2 = a3 = a4 = 15.
the sum of the lengths of all the edges of the cube 4a = 4 * 15 = 60 cm.
The surface area of a cube is equal to the sum of the areas of its six faces, i.e. area of a square with side a times six. The surface area of a cube is:
S = 6a ^ 2
S = 6 * 12 ^ 2 = 6 * 12 * 12 = 864 cm ^ 2
Answer: 864 cm ^ 2