10.
Answer: 42° and 138°
Steps: First find value of x by adding both equations and setting them equal to 180°:
3x + 12x - 30 = 180
15x - 30 = 180
15x = 210
x = 14
Next, put value of x into equations to find the angle:
3x
3(14)
42°
12x - 30
12(14) - 30
168 - 30
138°
11. Answer: 28°
Steps: Complementary angles add up to 90°, so subtract 62° from 90° to find its complementary angle.
90 - 62 = 28
12. Answer: Corresponding angles are congruent.