Please help need help with geometry homework!

Question

A right rectangular prism has length 9 cm, width 5 cm, and height 3 cm. If the length, width, and height are doubled, what happens to the surface area?

A.) The surface area is multiplied by 4.

B.) The surface area is multiplied by 5.

C.) The surface area is multiplied by 8.

D.) The surface area is doubled.

Need help very fast!

Answer 1

SA =2(lw+ wh+lh)

When each is doubled

New SA= 2 [(2l)(2w)+(2w)(2h)+(2l)(2h)=4[2(lw+wh+lh)]= 4 SA

So the answer is A, it does not depend on what the lengths of sides are.

For this particular problem, you may use the given values too