Question

Question #1eafd

Answer 1

Circumferance of a circle of radius `r` is given as, `2pir` and area as `pi r^2`

Given, `r=84/2 =42cm`

So,circumferance = `263.9 cm`

So,area =`5541.77 cm^2`

Answer 2

Circumference i s`C=264`cm
Area is `A=5544`sq.cm

Explanation:

Given:
diameter = `d=84`cm
Circumference is given by the formula
`C=pi(d)`
Considering `pi=22/7`
`C=pi(d)=(22/7) X 84`
`C=22 X 14`
`C=264`cm
Area is given by
`A=1/4pid^2`
`=(1/4)(22/7)84^2`
`A=5544`sq.cm

Answer 3

Circumference of the Circle `color(blue)(~~263.89" cm"` (2 decimal places)

Area of the Circle `color(blue)(~~5541.77" cm"^2` (2 decimal places)

Explanation:

Given:

Diameter of the Circle = `84" cm"`

Formula to find the Circumference and the Area of the Circle

Circumference = `pi d " units"`

Area = `(1/4)*pi d^2 " Sq. units"`

Circumference = `pi*84 " cm"`

Pi `(pi)` is a name given to the ratio of the circumference of a circle to the diameter.

Note that the value of `pi =(22/7)~~3.14159` (approximately)

`rArr (22/7)*84 " cm"`

`rArr 263.8937829 " Units"` (using the calculator)

Area = `(1/4)*pi*84^2`

`Area ~~ 5541.769441 " Sq.cm"` (using the calculator)

Hence, we can write our final answer as

Circumference of the Circle `color(blue)(~~263.89" cm"` (2 decimal places)

Area of the Circle `color(blue)(~~5541.77" cm"^2` (2 decimal places)