In fig., PA and PB are two tangents drawn from an external point P to a circle with centre C and radius 4cm. If PA≅PB, then the length of each tangent is: 4 cm, 3 cm, 5 cm, 6 cm

Given that PA and PB are two tangents drawn from an external point P. And a circle with center C and radius 4cm and PA≅PB. Join center C with A and B. Given PA and PB are tangents of the circle. Then PA⊥CA and PB⊥CB. Therefore, ∠CAP = 90° and ∠CBP = 90°. But given, ∠APB = 90°. Therefore, ∠CBA = 90°. Therefore, quadrilateral ABCD has all angles equal i.e. 90° and adjacent sides equal. Hence, it is a square. Therefore, length of each tangent will be 4 cm