Answer:
6) f=45
7) r=57
Explanation:
the angles of a triangle will always add up to 180 degrees. Therefore, for the first one the three inside angles have to be 30, 15, and 135. If 135 is the supplementary angle to f, 45 must be the degree of f.
Same idea for the second one. 180-143=37. so 37+86+r=180. solve for r to get 57.