Answer:
its 28
Step-by-step explanation:
C is the longest side which is 35 ye and b is 21 yd. Then you would subtract 21^2 from 35^2 and you would get 784. Then find the square root of 784 and you would get 28 as the answer! Good luck and have a great day or night!
The percent of change is 73.33 percent
You should be able to set up a proportion between the sides something like (18+x)/x=(56+21)/56