The triangles shown are similar. write a proportion that could be used to determine the missing length. explain why you set up your proportion the way that you did.

5/20= x/21
21*5=105
105/20= 21/4
=5.25
I used this proportion because it was the only one that had two of the sides incorporated on one side of the equation. Otherwise, two variables wouldn't be able to be solved for.

The answer is “faster”.