If two tangents inclined at an angle 60° are drawn to a circle of radius 3 cm, then the length of each tangent is
Given : A circle with center O and PA and PB are two tangents to the circle at point A and C from an external point P such that ∠APC = 60° [i.e. angle of inclination between two tangents] .
To Find : AP and PC
In △OAP and △OCP
AO = OC [ radii of same circle]
OP = OP [ common ]
AP = PC [ tangents through an external point to a circle are equal]
△OAP ≅ △OPC [ By Side Side Criterion]
∠APO = ∠OPC [Corresponding parts of congruent triangles are equal] [1]
Now, ∠APC = 60° [Given]
∠APO + ∠OPC = 60°
∠APO + ∠APO = 60° [By 1]
2∠AP0 = 60°
∠APO = 30°
Now, OA ⏊ AP [ As tangent at any point on the circle is perpendicular to the radius through point of contact]
∠OAP = 90°
So △AOP is a right-angled triangle
And we know that,
So,
[As OA is radius and equal to 3 cm]