Area of Circle/Examples/Radius 2

Example of Area of Circle

Let $C$ be a circle whose radius is $2$.

Then the area of $C$ is $4 \pi$.

Proof

From Area of Circle:

$A = \pi r^2$

Hence when $r = 2$ we have:

$A = \pi \times 2^2 = 4 \pi$

$\blacksquare$

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): function (map, mapping)
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): function (map, mapping)