Parallelogram
We are given a figure where a parallelogram has side lengths of
9r-6, 8r+3, and 4r+19
The first two sides are congruent because they are the opposite sides of a parallelogram, thus:
9r - 6 = 8r + 3
Subtracting 8r:
r - 6 = 3
Adding 6:
r = 9
The value of r is r = 9
Now find the length of EF that must be equal to the length of the side CD, thus EF = 4r + 19 = 4*9 + 19 = 55
EF = 55
