Question

AB,CD,EF are straight lines
AB is parallel to cd
work out the size of angle y

Answer 1

y = 108°

Explanation:

3x - 12 and 2x + 16 are corresponding angles and are congruent , then

3x - 12 = 2x + 16 ( subtract 2x from both sides )

x - 12 = 16 ( add 12 to both sides )

x = 28

so

3x - 12 = 3(28) - 12 = 84 - 12 = 72

3x - 12 and y are a linear pair and sum to 180° , that is

y + 3x - 12 = 180

y + 72° = 180° ( subtract 72° from both sides )

y = 108°