Answer:
Step-by-step explanation:
This was a lot of work, but the principles are fairly straightforward. Every triangle has interior angles that add to 180. For many of the questions, when two of the interior angles are know, just add them together and subtract from 180 to find the third angle.
7. The sum of interior angles is 108, so the third angle is 72. But the question want the angle on the other side. This is a straight line, so the sum of angles must be 180. x is therefor (180-72)=108
8. Identical situation: x = 133
9. Same again: x= 124
10. The second angle is 180-81 or 99. 180-99-19 = 62
11. Second angle is 65. x=74
12. 77
13. 35
14. (180-(35+71)) = 74
15. 66
