question_answer 1)

The diameter of a circle is a line, which joins two points on the circle and also passes through the centre of the circle. (In the figure given below, AB is a diameter of the circle, is its centre). Express the diameter of the    circle (d) in terms of its radius (r).                

Answer:

                Given, AB is diameter of the circle. Also, C is the centre of the circle and PC is the radius. We know that, diameter of a circle \[=2\times \]radius \[=2\times PC\] \[\Rightarrow \]\[d=2\times r\] \[\Rightarrow \]               \[d=2r\] Hence, the diameter of the circle in terms of its radius can be expressed as \[d=2r\].