Question

The radius of a circle is 8 cm. Find the length of a tangent drawn to this circle from a point at a distance of 17 cm from its centre.

Answer 1

Given:

r = 8 cm

d = 17 cm

Length of tangent = `sqrt(d² − r²)`

d = distance of the external point from the centre

r = radius of the circle

d² − r² = 17² − 8²

= 289 − 64

= 225

Length of tangent = `sqrt225`

= 15 cm