Linda joined cardboard pieces to make a square pyramid, as shown below. If the dimensions of the pyramid are tripled, which statement is true about the surface area of the new pyramid?

It will be three times the original pyramid’s surface area.

It will be one-third of the original pyramid’s surface area.

It will be nine times the original pyramid’s surface area.

It will be one-ninth of the original pyramid’s surface area.

Question

Linda joined cardboard pieces to make a square pyramid, as shown below. If the dimensions of the pyramid are tripled, which statement is true about the surface area of the new pyramid?

 It will be three times the original pyramid’s surface area.

 It will be one-third of the original pyramid’s surface area.

 It will be nine times the original pyramid’s surface area.

 It will be one-ninth of the original pyramid’s surface area.

hang254 · Answer

attachment

anonymous · Answer

It will be nine times the original pyramid’s surface area.

anonymous · Answer

What happens to the dimensions of the height if it is tripled?

anonymous · Answer

The height gets multiplied by 3.

hang254 · Answer

Thanks!

anonymous · Answer

So if the height of the triangles and the base of the triangles all triple

anonymous · Answer

Then the area increases by 3*3=9

anonymous · Answer

@hang254  always remember this is a ratio problem and to get the ratio of the surface area its simply $$(length  ratio)^{2}$$
and if in future you're asked ratio of the volume its simply: $$(length ratio)^{3}$$