Question

Which change will double the lateral surface area of a regular triangular pyramid with base length b, height h, and slant height l? double each side, b, of the base triangle while keeping the slant height, l, the same. double the height, h, of the pyramid while keeping each base length, b, the same?

Answer 1

The choice that will affect the surface area of the lateral face has to do with doubling ONLY one of the dimensions of the lateral face.

The second choice explains that the height is doubled while the length of the base remains unchanged. This is the correct answer.