Question

In below fig, determine the value of x.

Answer 1

Since sum of all the angles round a point is equal to 360°.Therefore

⇒ 3x + 3x +150 + x = 360°

⇒ 7x° = 360° -150°

⇒ 7x = 210°

⇒ x = `210/7`

⇒ x = 30°

Answer 2

In the given figure:

AOB is a straight line. Thus,∠AODand  ∠BODform a linear pair.

Therefore their sum must be equal to180°.

We can say that

 ∠AOD+∠BOD = 180°

It is given that ∠AOD=150°, substituting this value in equation above, we get:

`150° + x = 180°`

              ` x = 180° - 150°`

              `  x =30°`