+33 Hi. There's an easy way to do this with trigonometry, but I don't know if you need to solve it using trig or not, so I'll just help in the simpler way.
As I'm sure you know, angles that make up a horizontal line have to add up to 180 degrees. Therefore, the angle next to 139 must be 41, because 180-139 = 41.
A triangle's angles add up to 180, so 77+41 = 118, and 180 - 118 = 62. Therefore, c = 62 degrees.
Now that we have c, we can get b, because they form a horizontal line together.
c = 62, so 180 - 62 = 118 degrees (b).
a is an opposite angle of the 36 degrees at the bottom, so a = 36 degrees.
To summarize: a= 36, b = 118, c = 62.
Hope that helps you understand it better.
