Answer:
9. m ∠MNP = 56°
10. m ∠WXZ = 130°
11. m ∠ABC = 118°
12. m ∠ABC = 97°
Step-by-step explanation:
9.
2a = a + 28
2a - a = 28
a = 28
(a + 28)° = m ∠MNP
(28 + 28) = 56°
m ∠MNP = 56°
10.
5y = 2y + 78
5y - 2y = 78
3y = 78
y = 26
5y° = m ∠WXZ
(5 × 26) = 130°
m ∠WXZ = 130°
11.
(n + 7)° + (3n - 47)° = 180
n + 7 + 3n - 47 = 180
n + 3n + 7 - 47 = 180
n + 3n = 180 - 7 + 47
4n = 220
n = 55
(3n - 47)° = m ∠ ABC
((3 × 55) - 47) = m ∠ABC
(165 - 47) = 118°
m ∠ABC = 118°
12.
83 + 83 = 166
360 - 166 = 194
194 ÷ 2 = 97
x = 97°
m ∠ABC = 97°