PQ is a tangent at point C at circle with center o.if AB is a diameter

1.	PQ is a tangent at point C at circle with center o.if AB is a diameter and ACB-30 find PCA
Answer» In the given figure,In Δ ACO,OA=OC (Radii of the same circle)Therefore,ΔACO is an isosceles triangle.∠CAB = 30°\xa0(Given)∠CAO = ∠ACO = 30° (angles opposite to equal sides of an isosceles triangle are equal)∠PCO = 90° …(radius is drawn at the point ofcontact is perpendicular to the tangent)Now ∠PCA = ∠PCO – ∠CAOTherefore,∠PCA = 90° – 30° = 60°

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