Question

the lenght of a tangent from a point A at a distance 70 cm from the centre of a circle is 56 cm .find the circumference of the circle. ​

Answer 1

Name the point as B where he tangent touches the circle and take O as thecenter.

Now BOA is a right angled triangle with angle OBA = 90 degrees.

Therefore, by using Pythagoras theorem, we can find OB and we get OB = 42cm.

Now using the formula of finding the circumference,i.e 2(pi)r, we get the circumference as 264cm.