Question

What will the measure of third angle if other two angle are 30• and 40• ? Tick the correct option (A) 20• (B) 110• (C) 290• (D) 30•

Answer 1

Answer:

110

The sum of all the angles of a triangle is 180° so 180-(30+40)=110°

Answer 2

Required Answer :

Option (B) 110°

The third angle = 110°

Given :

• First angle = 30°
• Second angle = 40°

To find :

• The third angle

Solution :

Let,

• The third angle = x

The given geometric figure has 3 angles. So, consequently it has 3 sides.

Using formula,

• Sum of interior angles of polygon = (2n - 4) × 90°

where,

• n denotes the number of sides

⇒ 30° + 40° + x° = (2(3) - 4) × 90°

⇒ 70° + x = (6 - 4) × 90°

⇒ 70° + x = 180°

⇒ x = 180° - 70°

⇒ x = 110°

Substituting the value of x :

Third angle :

⇒ Third angle = x

⇒ Third angle = 110°

Therefore,

• The third angle = 110°