please help me answer this question from lesson circles in math
Answers
Step-by-step explanation:
Given:- PR and PS are tangent of a circle with centre O, where P is a point external to the circle.
To Prove:- ∠OPR = ∠ORQ
Proof:-
Now,
P is a point external to the circle,
Thus,
PR = PS
∴∠PRQ = ∠PSQ [Angles opposite to equal sides are equal] or [Properties of Isosceles Triangle] ---- 1
Now,
In ΔPRS,
∠PRQ + ∠PSQ + ∠RPS = 180° [Angle Sum Property]
From eq.1
∠PRQ + ∠PRQ + ∠RPS = 180°
2∠PRQ = 180° - ∠RPS
∠PRQ = (180° - ∠RPS)/2
∠PRQ = 90° - (∠RPS/2) ------ 1
Now, we know that,
OR ⊥ PR [Radius ⊥ Tangent at the point of contact]
Thus,
∠ORP = 90°
But,
∠ORP = ∠ORQ + ∠PRQ
90° = ∠ORQ + ∠PRQ
∴ ∠PRQ = 90° - ∠ORQ ----- 2
From eq.1 and eq.2 we get,
90° - ∠ORQ = 90° - (∠RPS)/2
- ∠ORQ = 90° - 90° - (∠RPS)/2
-∠ORQ = -∠RPS/2
Thus,
∠ORQ = ∠RPS/2
2∠ORQ = ∠RPS ------ 3
Now,
we know that,
A line drawn from the centre of a circle to an external point, bisects the angles formed by the two tangents,
Thus,
∠OPR = ∠OPS
Now,
∠RPS = ∠OPR + ∠OPS
∠RPS = ∠OPR + ∠OPR
∠RPS = 2∠OPR ------ 4
From eq.3 and eq.4 we get,
2∠ORQ = 2∠OPR
∠ORQ = (2∠OPR)/2
∴ ∠ORQ = ∠OPR
Hence proved
Hope it helped and believing you understood it........All the best