Question

find the area of a circle whose circumference is 52.8cm.
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Answer 1

Answer:

Area of circle=221.76cm²

$\rule{380}{2}$

Step-by-step explanation:-

Given:-

• Circumference of circle=52.8cm

$\rule{380}{2}$

To find:-

• Area of circle

$\rule{380}{2}$

Solution:-

To find the area of circle, first we have to find the radius of the given circle, which could be find by applying formula of circumference.

We have formula:

★ Circumference of circle=2πr

=> 52.8cm=2πr

$\sf\:=> 52.8cm=2\times\dfrac{22}{7}\times r$

$\sf\:=> 52.8cm\times\dfrac{7}{22\times2}=r$

$\sf\:=> 8.4cm=r$

Now put this value of radius of circle in the formula of area!

★ Area of circle=πr²

$\sf\:Area\:of\: circle=\dfrac{22}{7}\times8.4cm\times8.4cm$

$\sf\:Area\:of\: circle=221.76cm^{2}$

So the required area of circle is 221.76cm².

$\rule{380}{2}$

More important formulae:-

★ Area of rectangle=Length×Breadth

★ Area of square=Side²

★ Area of right angled triangle=½×Base×Height

★ Perimeter of rectangle=2(L+B)

★ Perimeter of square=4×Side

$\rule{380}{2}$

Answer 2

Given :-

• Shape = Circle
• Circumference of Circle = 52.8cm

To Find :-

• The Area of the Circle

Solution :-

⟹ Circumference of Circle = 2πr

⟹ 52.8 = 2 × 22/7 × Radius

⟹ 52.8 ÷ 2 = 22/7 × Radius

⟹ 26.4 = 22/7 × Radius

⟹ 26.4 × 7 ÷ 22 = Radius

⟹ 184.8 ÷ 22 = Radius

⟹ 8.4cm = Radius

Now,

⟹ Area of Circle = πr²

⟹ Area of Circle = 22/7 × (8.4)²

⟹ Area of Circle = 22/7 × 70.56

⟹ Area of Circle = 22 × 10.08

⟹ Area of Circle = 221.76cm²

Therefore, Area of Circle = 221.76cm²

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★ Additional Info :

Formulas Related to Circle :

• Circumference of Circle = 2πr
• Area of Circle = πr²
• Diameter of Circle = 2r
• Radius of Circle = D/2

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