Answer:
He has the side lengths in the wrong place in the cosine ratio. (1st Answer on Edgen)
Step-by-step explanation:
16 is 1,600 in percent form
I hope this helps you
there is a 5,12,13 triangle
x^2=5^2+12^2
x^2=25+144
x^2=169
x=13
Since they’re outside corresponding angles you can just set the 2 equations up to each other and solve for x.
5x + 20 = 3x + 60
-3x -20
2x = 40
x=2