Question

Find the area of the following circle IN BOTH TERMS OF PI and 3.14:Find the area of a circle with diameter 20cm.

Answer 1

Given to us that:–

• Circle with Diameter 20 cm

Step by step:–

By using the formula:

Area (A) of a circle ,

`\underbrace{\bf{A=\pi r^2}}`

➱ r - > radius

➱ r -> diameter ÷ 2 = 20 ÷ 2 = 10 cm

By substituting the known values ,

➱
`\mathsf{A = \pi \cdot r^(2)}`

➱
`\mathsf{A = \pi \cdot 10^(2)}`

➱
`\sf{A=\pi \cdot 100}`

➱
`\mathsf{A = 100\pi}` Area in terms of pi

✯ Now lets find the area when pi = 3.14

➱
`\mathsf{A = 3.14 \cdot 10^2}`

➱
`\mathsf{A = 3.14 \cdot 100}`

➱
`\mathsf{A=314 \: cm}`

Henceforth, Area in terms of pi = 100pi; Area for pi = 3.14 = 314 cm

Answer 2

The area of the circle in terms of pi = 100π cm²

The area of the circle is 314 cm².

Explanation:

Given that,

The diameter of the circle = 20 cm.

We need to find out the value of radius of the circle in order to find the area of the circle.

To find the radius of the circle :

Radius, r = diameter / 2

⇒ r = 20/2

⇒ r = 10 cm.

Therefore, the radius of the circle is 10 cm.

To find the area of the circle :

Area of the circle = πr²

where,

• π has the default value of 3.14
• r is the radius of the circle.

Area of the circle in terms of Pi :

⇒ π × (10)²

⇒ π × 10 × 10

⇒ 100π

The area of the circle in terms of pi = 100π cm²

Area of the circle = 3.14 × 100

⇒ 314 cm²

The area of the circle is 314 cm².