#15 i know how to solve it i just dont know how to erite the equation out

Here's 2 (almost) equations:
m<1 = m<3
m<1 + m<2 + m<2 + m<3 = 360

I got the first one because angle 1 and 3 are on opposite sides, so they must be equal. I got the second one because 2 and (unlisted) 4 must be equal, and all of the angles added must be 360.

Is this what you wanted?..