Mathematics
In the given figure, O is the centre of the circle. If QR = OP and ∠ORP = 20°, find the value of x giving reasons.

Circles
2 Likes
Answer
Given,
⇒ QR = OP
⇒ QR = OQ (As, OP = OQ = Radius of circle)
⇒ ∠QOR = ∠ORQ = 20° (Angles opposite to equal sides of a triangle are equal)
Exterior angle in a triangle is equal to the sum of two opposite interior angles.
∴ ∠OQP = ∠QOR + ∠ORQ = 20° + 20° = 40°.
As OP = OQ, ∠OPQ = ∠OQP
⇒ ∠OPQ = 40°
⇒ ∠OPR = 40°.
Exterior angle in a triangle is equal to the sum of two opposite interior angles.
In triangle OPR,
∴ x° = ∠OPR + ∠ORP = 40° + 20° = 60°.
Hence, the value of x = 60.
Answered By
3 Likes
Related Questions
In the adjoining figure, AB = AC = CD and ∠ADC = 35°. Calculate :
(i) ∠ABC
(ii) ∠BEC

The exterior angles B and C in ΔABC are bisected to meet at a point P. Prove that ∠BPC = 90° − . Is ABPC a cyclic quadrilateral ?
In the given figure, I is the incentre of Δ ABC. Here AI produced meets the circumcircle of Δ ABC at D. If ∠ABC = 55° and ∠ACB = 65°, calculate :
(i) ∠BCD
(ii) ∠CBD
(iii) ∠DCI
(iv) ∠BIC

In the given figure, ∠DBC = 58° and BD is a diameter of the circle. Calculate :
(i) ∠BDC
(ii) ∠BEC
(iii) ∠BAC
