These are all right triangles, and since there are 180 degrees in a triangle, there are 90 'spare' degrees.
For the first one with side length 13 and degree 52. 90 - 52 = 38 degrees.
For the one with length 12 and degree 37. 90-37 = 53 degrees.
For the one with side lengths 10 and 13. Use tangent. tan(a) = 13/10 = 1.3; tan(b) = 10/13 = .769
ceta is 37 and
https://www.mathopenref.com/trigtangent.html
For the one with angle 73. 90-73 = 17.