Answer: The scale is 5/4
Explanation:
To determine the scale factor, you have to locate which sides are similar to each other .
the side length with 20 is congruent to 16
15 is similar to 12 and 10 is similar to 8.
And to get from triangle A to triangle B of any side length, we need to multiply by a certain number which is the scale factor.
And to find that number we will divide the side length of any side in triangle A by the similar side to it in triangle B.
20/ 16 = 5/4
15/ 12 = 5 / 4
10 / 8 = 5/4