In the figure below, ΔABC and ΔDEF are similar triangles

In the figure below, ΔABC and ΔDEF are similar triangles with the given side lengths in meters. What is the perimeter, in meters, of ΔDEF ?

  1. 3
  2. 8
  3. 11
  4. 12
  5. 13

Answer

The correct answer is C.

The shorter two sides are the same length in ΔABC, so the same thing has to happen in any triangle similar to it. That means that DE is the same length as EF, which is 3 meters.

Then, the perimeter of ΔDEF is 3 + 3 + 5 = 11 meters.