Answer:
B) 131°
Step-by-step explanation:
-4a + 139 = 4a + 123 because they are vertical angles
-4a + 139 = 4a + 123
reduce:
8a = 16
a = 2
4(2) + 123 = 131°
2400sq ft
20×2 and 30×2
40×60
2400 sq ft
c
