Question

if A and B are complementary angles and B and C are supplementary angles if the average of a and c is 85 then a + b + C is equal to
a. 200
b. 220
c. 210
d. 240

Answer 1

A+B=90°
= A=90-B___eq1

B+C=180
C=180-B____eq2

85=A+C/2
85=90-B+180-B/2
170=270-2B
2B=100
B=50
therefore
a+b+c=220