Question

Please answer question 10

Answer 1

it is given angle aoc and angle boc form a linear pair

a+b= 180 ( mark this 1)

a-b = 90 (mark this 2)

now transpose everything in 1, other than a

a= 180-b

now put this in 2

a-b = 90

180-b -b = 90

-2b = -90

b = 45

Hence angle a will be 180-45 = 135.