(i) Since angles y and 120° form a linear pair.
y + 120° = 180°
y = 180° – 120°
y = 60°
Now using the angle sum property of a triangle, we have
x + y + 50° = 180° x + 60° + 50°
= 180° x + 110°
= 180° x
= 180° – 110°
= 70°
x = 70°
y = 60
(ii) Using the angle sum property of triangle, we have
50° + 60° + y = 180°
110° + y = 180°
y = 180° – 110°
y = 70°
Again x and y form a linear pair
∴ x + y = 180° x + 70°
= 180° x
= 180° – 70°
= 110°
∴ x = 110°; y = 70°
