Question

The length of the tangent from point A to a circle, of radius 3 cm, is 4 cm. The distance of A from the centre of the circle is ______  

विकल्प

• `sqrt7` cm

• 7 cm

• 5 cm

• 25 cm

Answer 1

The length of the tangent from point A to a circle, of radius 3 cm, is 4 cm. The distance of A from the centre of the circle is 5 cm.

Explanation:

Given that AB = 4 cm, OB = 3 cm

To find OA

Applying Pythagoras theorem to triangle OAB

OB² + AB² = OA²

3² + 4² = OA

OA² = 25

OA = 5 cm

Therefore the distance of A from the centre of the circle is 5 cm.