Question

What is the difference in the area of a circle with diameter of 4 m and a circle with diameter 6

Answer 1

So the formula for the area of the circle is $A=\pi r^2$ . To find the radius is divide the diameters by 2, which in this case its 2 and 3. Now we can find the areas.

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

$A= \pi3^2 \\ A=9 \pi$


Now just subtract the areas: $9 \pi -4 \pi =5 \pi$


The difference in areas is 5 pi, or 15.71.