We are given the ratio
A : C = 4 : 1
where
A=area = pi*r^2
![A=\pi r^2](https://img.qammunity.org/2023/formulas/mathematics/high-school/lcgfavc89jro4qntamn2b9gfliomu1jwuf.png)
C=circumference = 2pi*r
![C=2\pi r](https://img.qammunity.org/2023/formulas/mathematics/high-school/noytl63lm1q06t23qsdkycir68uwxrmxzb.png)
then
![\pi r^2:2\pi r=4:1](https://img.qammunity.org/2023/formulas/mathematics/college/woykm6gwy2cxyh9xdc28veiiqohgvi4ut9.png)
express as afraction
![(\pi r^2)/(2\pi r)=(4)/(1)](https://img.qammunity.org/2023/formulas/mathematics/college/sixhn43fo0la7h2eo4bdx7yuewtjz4e41u.png)
thus
![(r)/(2)=4](https://img.qammunity.org/2023/formulas/mathematics/college/hxfcyjc0sbunwfoywtqh7uxp6r8326i0u3.png)
![r=2*4=8](https://img.qammunity.org/2023/formulas/mathematics/college/b39joaup4br9l0fpx66jpw5confnwjjl8o.png)
then the radius is r=8cm
B)Circumference
![C=2\pi r=2\pi8=16\pi](https://img.qammunity.org/2023/formulas/mathematics/college/ch5gg2kspylpq1vqikh5hyc5i6gr8beki6.png)
![C=16*3.14=50.24](https://img.qammunity.org/2023/formulas/mathematics/college/9hxmwvz5f7os0wig7rjvyagkz6e5k2o0sw.png)
the circumference is 50.2 cm
C)Area
![A=\pi r^2](https://img.qammunity.org/2023/formulas/mathematics/high-school/lcgfavc89jro4qntamn2b9gfliomu1jwuf.png)
![A=3.14*8^2=200.96](https://img.qammunity.org/2023/formulas/mathematics/college/sbbb6rtif1n1kcgonz7ftgvomrmlnbzt1j.png)
then the Area is 201.0 cm^2
D)Volume
![V=(4)/(3)\pi r^3](https://img.qammunity.org/2023/formulas/mathematics/high-school/zraet4fw93vx9gjz3iextthjo546ibcpwc.png)
![V=(4)/(3)*3.14*8^3](https://img.qammunity.org/2023/formulas/mathematics/college/y0v179jsvscjqwix6g4rof9cbmvvowzamd.png)
![V=2143.573](https://img.qammunity.org/2023/formulas/mathematics/college/13rdlkiv5hztawaiihtwjmms404m6lf56p.png)
then the volume is
V=2143.6 cm^3