The angle 3 of the parallelogram is: m∠3 = 121°
How to find the angle of the parallelogram?
We are given the angles of the paralleogram as:
m∠2 = 4x - 15
m∠4 = 2x + 23
We know that opposite angles of a parallelogram are congruent. Thus:
4x - 14 = 2x + 23
2x = 37
x = 18.5
Thus:
m∠2 = 4(18.5) - 15
m∠2 = 59°
m∠3 is supplementary to m∠2 and as such:
m∠3 = 180 - 59
m∠3 = 121°