Answer:
(3) 83° , (4) 85°
Step-by-step explanation:
The sum of the 3 angles in a triangle is 180°
(3)
sum the 3 angles , equate to 180 and solve for x
87 + x + 43 + 54 = 180 ( simplify left side )
x + 184 = 180 ( subtract 184 from both sides )
x = - 4
Then
87 + x = 87 - 4 = 83°
(4)
Similarly
5 + 10x + 60 + 35 = 180 ( simplify left side )
10x + 100 = 180 ( subtract 100 from both sides )
10x = 80 ( divide both sides by 10 )
x = 8
Then
5 + 10x = 5 + 10(8) = 5 + 80 = 85°
