Given the diagram of parallelogram lmno, solve for s.
a.
20
b.
30
c.
40
d.
120

< o and < m are congruent because opposite angles are congruent
3t - 15 =  2t + 10
3t - 2t = 10 + 15
t = 25

3t - 15 = 3(25) - 15 = 75 - 15 = 60...< m = 60

< m and < o are consecutive angles and they are supplementaryso they add up to 180
< m + < o = 180
60 + < o = 180
< o = 180 - 60
< o = 120

3s = 120
s = 120/3
s = 40