Question

One circular table has a diameter of 9ft, and another circular table has a diameter of 14ft. How much greater is the area of the larger table? round to the nearest whole number.

Answer 1

$Area \ of \ a \ Circle : \\ \\A= \pi r^2 \\ \\ diameter : \ d_{1}= 9 \ ft \\ radius : r_{1} =\frac{d_{1}}{2}=\frac{9}{2}=4.5 \ ft \\ \\ d_{2}= 14 \ ft \\ radius : r_{2} =\frac{d_{1}}{2} =\frac{14}{2}=7 \ ft \\ \\A_{1}= (4.5)^2 \pi=20,25 \ cdot 3.14 = 63.585 \ ft^2 \\ \\A_{2}= 7^2 \pi=49 \cdot 3.14 = 153.86 \ ft^2 \\ \\ A_{2}-A_{1}= 153.86 - 63.585 = 90.275 \approx 90 \ ft^2$

Answer 2

Area of circle= πr²
r-radius

A1-area of table with diameter 9ft
A2-area of circle with diameter 14ft
d=2r

A1=π*(4,5)²=20,25π
A2=π*7²=49π

A2-A1=49π-20,25π=28,75π=90,275≈90ft²