Using the given information, find the value of x in the following figure :

Considering △ABC and △ADC,

∠ABC = ∠ADC = 20° (∵ angles in same segment are equal.)

∠DOC = ∠DOB = 90° (As DA is perpendicular to BC)

We know that sum of angles in a triangle is 180°.

Considering △DOC,

⇒ ∠ODC + ∠DOC + ∠OCD = 180°
⇒ 20° + 90° + x° = 180°
⇒ x° + 110° = 180°
⇒ x° = 180° - 110°
⇒ x° = 70°

Hence, the value of x = 70°.