Question

from point p two tangents pa and pb are drawn to a circle with centre o if op is equal to diameter of the circle prove that pab is an equilateral triangle

Answer 1

I don't know. And I did not anderstant

Answer 2

PA and PB are tangents
OA ⊥ PA
∠ OAP = 90 
㏑ Δ OPA, SIN ∠OPA= OA ÷ OP = r÷2r 
                 SIN ∠OPA = 1÷2 
                 ⇒ SIN 30