We need to prove that the length of tangents drawn from an internal point to a circle are equal Given circle (0, r)
To prove AB = AC
Proof : In triangle(s) AOB and AOC
∠OBA = ∠OCA = 90° (Tangent is perpendicular to centre of circle) OA = OA = {common side}
OB = OC = r [equal radius]
Using RHS congruence criterion rule
Δ AOB ≅ Δ AOC
AB = AC
Hence proved.
