Data: The tangents drawn at the ends of a diameter of a circle are parallel.
AOB is the p diameter in the circle with centre ‘O’.
Tangent PAQ is at the end point A, and
Tangent RBS is A at the end point B.
OA is radius,
PAQ is tangent
∴ ∠PAO = 90°
OB is radius, RBS is tangent.
∴ RBO = 90°
Now, ∠PAO + ∠RBO = 90° + 90° = 180°
AB intersects straight lines PAQ and RBS.
Sum of a pair of interior angles is 180°.
Hence these lines are parallel to each other.
∴ PQ || RS proved..
