tolong jawab nomer 37-40,beserta caranya!!!

37. 50 derajat + 90 derajat + x = 180 derajat
x = 180 - 140 = 40 derajat (A)
38. 2/5 × 90 = 36 derajat (A)
39. 6P + 12 = 90
6P = 78
P = 13 derajat (D)
40. 12 - 8 = 4
4 × 30 derajat = 120 derajat (C)