Question

If the scale factor used was k and the perimeter of the pink trapezoid was P, what would the perimeter of the blue trapezoid be?

Answer 1

kP

Explanation:

We assume the dimensions of the blue trapezoid are those of the pink trapezoid multiplied by k. If each of the sides is multiplied by k, their sum, the perimeter, is multiplied by k. (The distributive property tells you that.)

... (s1 +s2 +s3 +s4) = P

... (k·s1 +k·s2 +k·s3 +k·s4) = k(s1 +s2 +s3 +s4) = kP

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Caveat

We cannot tell from the description which trapezoid is the reference, and which is the one that is the reference multiplied by k. If the above is a wrong guess, then the perimeter is P/k.