Find the value of variable x from the below diagrams.Angle at ‘O’

1.	Find the value of variable x from the below diagrams.Angle at ‘O’ is straight angle
Answer» Straight angle = 180° ∠ AOB = 180° ∠ AOB + ∠ BOD = 180° x + 30° + x = 180° ⇒ 2x + 30° = 180° ⇒ 2x + 30° – 30° – 180°- 30° (Subtract 30° on both sides) ⇒ 2x = 150° ⇒ 2x/2 = 150°/2 (Divide by 2 on both sides) ∴ x = 75°

Find the value of variable x from the below diagrams.Angle at ‘O’ is straight angle

Answer»

Straight angle = 180°

∠ AOB = 180°

∠ AOB + ∠ BOD = 180°

x + 30° + x = 180°

⇒ 2x + 30° = 180°

⇒ 2x + 30° – 30° – 180°- 30° (Subtract 30° on both sides)

⇒ 2x = 150°

⇒ 2x/2 = 150°/2 (Divide by 2 on both sides)

∴ x = 75°