" Suppose you are given a circle.Give a construction to find its centre."

Suppose you ar given a circle. Give a construction to find its centre.

Suppose you are given a circle. Describe a method by which you can find the centre of this circle.

Suppose you know the area of a square. How can you find its perimeter?

Find the radius of the circle (xcosalpha+ysinalpha-a)^2+(xsinalpha-ycosalpha-b)^2=k^2,ifalpha varies, the locus of its centre is again a circle. Also, find its centre and radius.

Suppose you know the perimeter of a square. How can you find its area?

How can you draw the tangent to a circle at a given point when the centre of the circle is not known?

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

You are given the following three lenses. Which two lenses will you use as an eye piece and as an objective to construct an astronomical telescope? Give reasons.

For the construction of a tangent to a circle without using its centre, the property used is