Question

In a cyclic quadrilateral PQRS the ∠SPQ = 120° and ∠PQR = 80°, then find the ∠QRS.
1. 80° 
2. 40°
3. 60°
4. 120°

Answer 1

Correct Answer - Option 3 : 60°

Given:

∠SPQ = 120°

∠PQR = 80°

Formula used:

Sum of opposites angles of cyclic quadrilateral = 180° 

Calculations:

⇒ ∠SPQ + ∠QRS = 180° 

⇒ ∠PQR + ∠RSP = 180° 

⇒ ∠QRS = 180° - ∠SPQ

⇒ ∠QRS = 180° - 120° 

⇒ ∠QRS = 60°

∴ The value of ∠QRS is 60°.