pq is the diameter.if angle pqr =65,angle rps=25 and angle qpt=60 then find angle rpq,prs,psr and pqt
The given information can be represented as,
Given: ∠pqr = 65°, ∠rps = 25° and ∠qpt = 60°
∠prq is an angle in a semicircle.
∴ ∠prq = 90° [Angle in a semicircle is 90º]
In Δpqr,
∠pqr + ∠prq + ∠rpq = 180° [Angle sum property]
⇒ ∠rpq = 180° – (90° + 65°) = 25°
In cyclic quadrilateral pqrs,
∠pqr + ∠psr = 180° [ Sum of opposite angles in cyclic quadrilateral is 180°]
⇒ ∠psr = 180° – 65° = 115°
In Δprs,
∠prs + ∠psr + ∠rps = 180° [Angle sum property]
⇒ ∠prs = 180° – (115° + 25°) = 40°
∠ptq = 90° [Angle in a semicircle is 90º]
In Δptq,
∠ptq + ∠pqt + ∠qpt = 180° [Angle sum property]
⇒ ∠pqt = 180° – (90° + 60°)
⇒ ∠pqt = 180° – 150°
⇒ ∠pqt = 30°
∴ ∠rpq = 25°, ∠prs = 40°, ∠psr= 115° and ∠pqt = 30°