Posts

Showing posts with the label Tangents from external point to the circle.

Tangets from external point to the circle are equal

Image
  Prove that the length of the tangents drawn from an external point to a circle are equal. .  Answer: Given : Let AP and BP be the two tangents drawn from external point P to the circle with centre O. To Prove : AP = BP Proof : In  Δ  AOP and  Δ BOP OA = OB (radii)  ∠ O A P = ∠ O B P = 90 ∘   (Line drawn from from center to the tangent through the point of contact is perpendicular)  OP = OP (common) ∴ Δ A O P ≅ Δ B O P  (R.H.S.)  ∴  AP = BP ( C P C T )  Therefore the length of the  tangents drawn from an  external point to a circle are  equal.