Question

The circumference of a circle is 22 cm.

What is the area of 1o of the circular region?
(Use = 2)
O 2.2 cm2
O 3.5 cm2
O 3.85 cm2
0 38.5 cm2

Answer 1

`\bf \: Circumference \: of \: a \: circle = 2\pi \: r`

`\implies22 = 2 * (22)/(7) r`

`\implies22 = (44)/(7) * r`

`\implies \: r = (22 * 7)/(44)`

`\implies \boxed{ r = (7)/(2) }`

Now,

`\bf \: Area \: of \: circle = \pi {r}^(2)`

`\rightarrow \: (22)/(7) * ({ (7)/(2)) }^(2)`

`\rightarrow (22)/( \cancel7) * \frac{ \cancel{49}}{4}`

`\rightarrow \: 22 * (7)/(4)`

`\rightarrow \: 11 * (7)/(2)`

`\rightarrow (77)/(2)`

`\rightarrow \: 38.5 \: cm {}^(2)`

Area of rectangle = 38.5 cm².