Question

The diagram shows three straight lines work out the size of angles a, b and c.

Answer 1

a = 21°

b = 70°

c = 89°

Explanation:

a = 21° as vertically opposite angles are equal

to work out b:

angles on a straight line add up to 180

b + 110 = 180

b = 180 - 110

b = 70°

to work out c:

the sum of angles in a triangle add up to 180

we have a and b

21 + 70 + c = 180

91 + c = 180

c = 180 - 91

c = 89°