Given :-
- diameter = 20.5 ft
- π = 3.14
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
To find :-
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
Solution:
To find area first we should know value of radius.
Diameter is given , and from diameter we can find value of radius.
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
We know :-
![\bf \ddag\boxed{\rm Diameter =2 \: radius } \bf \ddag](https://img.qammunity.org/2023/formulas/mathematics/high-school/r87xuo38yzypxiageo9c0z75n7gbktm63z.png)
By using this formula we can find radius.
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
![\hookrightarrow\sf Diameter =2 \: radius](https://img.qammunity.org/2023/formulas/mathematics/high-school/sdn43i3mpdw78rp3wtn0rb3kpjagfccaj4.png)
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\hookrightarrow\sf 20.5 =2 \: radius](https://img.qammunity.org/2023/formulas/mathematics/high-school/ahptyqwclwjsho9t8r83qgs4nu05gs0cji.png)
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\hookrightarrow\sf (205)/(10) =2 \: radius](https://img.qammunity.org/2023/formulas/mathematics/high-school/qtr5k71vp5sz6d3o1ecb12m86gzxkebuz0.png)
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\hookrightarrow\sf \cancel(205)/(10) =2 \: radius](https://img.qammunity.org/2023/formulas/mathematics/high-school/dunwizdb293h6ihn4vs6wh7e8neekfqbvm.png)
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\hookrightarrow\sf (41)/(2) =2 \: radius](https://img.qammunity.org/2023/formulas/mathematics/high-school/5cdhjovw35xuqecw8hzlg7f7see4xfny33.png)
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\hookrightarrow\sf2 \: radius = (41)/(2)](https://img.qammunity.org/2023/formulas/mathematics/high-school/j0ejttpx123kuctii58v5cj6ga0y3g8i1h.png)
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\hookrightarrow\sf \: radius = (41)/(2 * 2)](https://img.qammunity.org/2023/formulas/mathematics/high-school/tg478c4lv8bhuvpe9o7u3bfgwuw309oiof.png)
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\hookrightarrow\sf \: radius = (41)/(4)](https://img.qammunity.org/2023/formulas/mathematics/high-school/x9qnjff3936z23oro1b656tz0y7yg0gs5s.png)
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\hookrightarrow\bf \: radius = 10.25](https://img.qammunity.org/2023/formulas/mathematics/high-school/dnb1lm13rfloeza2lmw6c490vhklpy3rob.png)
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
Now let's find Area
we know :-
![\bf \ddag\boxed{\rm Area = \pi radius {}^(2) } \bf \ddag](https://img.qammunity.org/2023/formulas/mathematics/high-school/7p2arwqqm91afpep2ee8nvsf872alewvlr.png)
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
So:-
![\\](https://img.qammunity.org/2023/formulas/spanish/high-school/3sx26fznv84e4ulbgeqvxi5ztv7h0mnzrw.png)
![\dashrightarrow \sf Area = \pi radius {}^(2)](https://img.qammunity.org/2023/formulas/mathematics/high-school/yl3jzuzq3qamcgt62fcjtoxgsxa7u9r57q.png)
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
![\dashrightarrow \sf Area = \pi (10.5) {}^(2)](https://img.qammunity.org/2023/formulas/mathematics/high-school/kavgq6lrw5zc85210bp20eh5ckugd4yfud.png)
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
![\dashrightarrow \sf Area = \pi * 10.5 * 10.5 \\](https://img.qammunity.org/2023/formulas/mathematics/high-school/6aqql11fquxhj52j2zbogbh3kd4wzdmfic.png)
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
![\dashrightarrow \sf Area = \pi * 110.25 \\](https://img.qammunity.org/2023/formulas/mathematics/high-school/mz80vtdkrjz3sza86fcdtwd2tm8t327aqy.png)
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
![\dashrightarrow \sf Area = 3.14 * 110.25 \\](https://img.qammunity.org/2023/formulas/mathematics/high-school/4lx797r2ex5dq2d1f0r8itxpm1xb6dgcxs.png)
![\\ \\](https://img.qammunity.org/2023/formulas/spanish/high-school/3smwgzm5kcwhalsj7lj64e5ajokjvn8r8h.png)
![\dashrightarrow \bf Area =346.19~ {ft}^(2) \{approx\}\\](https://img.qammunity.org/2023/formulas/mathematics/high-school/kzx42nt4mnryy0c6gxlb543hjnq35uqp2s.png)