Question

The two triangular prisms shown are similar. The dimensions of the larger prism were multiplied by a scale factor of to create the smaller prism.


When the large prism was reduced, the surface area changed by a factor of
64/125, 16/25, 4/5, 10/8, answer choices

Answer 1

If the linear scale factor is 4/5, surface areas scale by the square of the linear factor. So the surface area is multiplied by (4/5)^2 = 16/25.

(For reference, volumes would change by (4/5)^3 = 64/125.)