Answer:
y = 37
Step-by-step explanation:
the 3 angles lie on a straight line and sum to 180°
sum the 3 angles and equate to 180
y + 29 + 40 + 2y = 180 , that is
3y + 69 = 180 ( subtract 69 from both sides )
3y = 111 ( divide both sides by 3 )
