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If two tangents inclined at an angle 60° are drawn to a circle of radius 5 cm, then what is the length of each tangent?

Solution

✅ Correct Option: 2

The circle has radius 5 cm. Two tangents are drawn from an external point, with an angle of 60° between them.

Let O be the center of the circle, P be the external point where the tangents meet, and A and B be the points where the tangents touch the circle.


The line OP bisects the angle between the two tangents.

Since angle APB = 60°:

Angle OPA = 60°2\frac{60°}{2}

Angle OPA = 30°


Consider triangle OAP:

The tangent is perpendicular to the radius at the point of contact, so angle OAP = 90°.

OA = 5 cm (radius)

PA = length of tangent (to find)


In right triangle OAP:

tan⁡(30°)=OAPA\tan(30°) = \frac{OA}{PA}

13=5PA\frac{1}{\sqrt{3}} = \frac{5}{PA}

PA=53PA = 5\sqrt{3} cm

Therefore, the length of each tangent is 535\sqrt{3} cm.

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