Find the value of x in the following figures.

i.

ii.

i. In the given figure,

AB is a straight line, hence all the angles formed on it are supplementary.

⇒ (x – 20)° + x° + 40° = 180°

⇒ 2x + 20° = 180°

⇒ 2x = 180° - 20°

⇒ 2x = 160°

⇒ x = 80°

ii. In the given figure,

AB is a straight line, hence all the angles formed on it are supplementary.

⇒ (x + 30)° + (115 – x)° + x° = 180°

⇒ x + 145° = 180°

⇒ x = 180° - 145°

⇒ x = 35°