SOLUTION: Find the measure of <M. Round your answer to the nearest degree. Can someone help me please. Copy and paste this link to see the picture please > http://prntscr.com/6c80af

Algebra ->  Triangles -> SOLUTION: Find the measure of <M. Round your answer to the nearest degree. Can someone help me please. Copy and paste this link to see the picture please > http://prntscr.com/6c80af       Log On


   

Question 952470: Find the measure of Can someone help me please.
Copy and paste this link to see the picture please > http://prntscr.com/6c80af
Thank you.
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
Using Law of Cosines:
k=side opposite K=20ft; l=side opposite L=10ft; m=side opposite M=15ft
cos%28M%29=%28k%5E2%2Bl%5E2-m%5E2%29%2F%282kl%29
cos%28M%29=%2820ft%5E2%2B10ft%5E2-15ft%5E2%29%2F2%2820ft%29%2810ft%29
cos%28M%29=%28400ft%5E2%2B100Ft%5E2-225ft%5E2%29%2F%28400ft%5E2%29
cos%28M%29=%28275ft%5E2%29%2F%28400ft%5E2%29=0.6875
Angle M=cos%5E-1%280.6875%29=46.6degrees
ANSWER: Measure of angle M is 47 degrees.