Question

. If the area of a circle with radius of 1 is π square units, what is the area of a circle with radius 3 units? With radius 10 units? With radius r units?

Likewise, if the circumference (perimeter) of a circle is 2 units, what is the circumference of a circle with radius 3? With radius 7? With radius r?

Answer 1

the equation for the area of a circle with given radius r is \[\pi r ^{2}\]...so substitue for r=3 and r=10
like wise perimetre is \[2\pi(r)\] so substitue value and find :)