I got 30. If you set M and I equal to each other and solve you get 25. If you substitute 25 for t you get 60. L and I should be supplementary so if you subtract 60 from 180 you get 120. Lastly, since you're solving for r, you need to divided 120 by 4 to get 30.
So here is how we are going to solve for r. In a parallelogram, given angles L and N are equal in measure, as well as angles M and O. Angles L and O are supplementary angles, as well as M and N. So the first thing we are going to do is to solve for t first. 3t-15=2t+10 3t-2t=10+15 t=25 Angle O : 2t + 10 2(25)+10 = 60 Adding L and O together gives you 180 so
4r+60=180
4r=120
r=30 And 30*4=120
So r = 30 and angle L = 120 Hope this answers your question.
