Question

Find the length of tangent from a point 15cm away from the centre of a circle with radius 9cm

Answer 1

The answer is 12 cm because the distance from centre would become hypotenuse and the radius would be a side. then 9^2 +t^2 = 15^2
81 + t^2 = 225
t^2= 144
t=12

Answer 2

Radius of the circle = 9 cm
Distance between centre and the point = 15 cm
Length of the tangent be x

By Pythagoras theorem,
15² = 9² + x²
225 = 81 + x²
x² = 225 - 81
x² = 144
x = √144
x = 12 cm

The length of the tangent = 12 cm