Prove that the tangents drawn at the ends of a diameter of a circle are parallel.
To Prove: CD || EF

Proof: CD is the tangent of the circle at point A.
⇒ CD⟘ OA
⇒ ∠ OAD = 90° and ∠ BAD = 90° ... (1)
EF is the tangent to the circle at point B.
⇒ EF ⟘ OB
⇒ ∠ OBE = 90° and ∠ ABE = 90° … (2)
From (1) and (2),
∠ BAD = ∠ ABE = 90°
These are alternate angles.
Therefore, CD || EF
Couldn't generate an explanation.
Generated by AI. May contain inaccuracies — always verify with your textbook.