Question

The surface area of a triangular pyramid is 80 m2. If the pyramid is enlarged by a scale factor of 2, what is the surface area of the scaled image? 240 m2 640 m2 160 m2 320 m2

Answer 1

If scale factor is 2 the area is increased by a factor of 2^2 . That is 4 times.

Therfore the surface area of the image is 80 * 4 = 320 m^2.

Answer 2

If the linear dimensions are enlarged by a scale factor k, the areas are enlarged by a scale factor k^2.

Here, the linear dimensions were enlarged by a factor of 2. Then, the area was enlarged by a factor of 2^2. 2^2 = 4, so multiply the original area by 4 to find the new area.

80 m^2 * 4 = 320 m^2