Because this is a regular parallelogram, the angles you are solving for are congruent or equal to each other.
(3y+27) = (5y-3)
Use basic algebra to solve for the values.
27 + 3 = 5y - 3y
30 = 2y
15 = y
Now plug into one unknown angle:
(3(15)+27) = ?
= 72
72 degrees is the value of angle A
To find angle B, simply take 180 and subtract 72 from it.
180 - 72= 108
The value of angle B is 108 degrees.
