You got the angles in front of each other are equal rule down. Good job.
Other rule is that the angle on top of the line should equal 180. Like angle 3 + 79.4+37.3 should equal 180.
Same thing with the angle 4: 180-37.3= 142.7
Next the middle part is a triangle. Sum of all 3 angles should be 180. 79.4+37.3 + angle 1 needs to equal 180.
Thats all you need to know for these