Question

Diameter of a circular garden is 9.8 m. Find its area and circumference.​

Answer 1

Answer :

• Area is 75.46 m²
• Circumference is 30.8 m

Given :

• Diameter of circular garden is 9.8m

To find :

• Area and Circumference

Solution :

• Diameter = 9.8m

First we need to find radius ,

As we know that,

• Radius = Diameter/2

》Radius = Diameter/2

》9.8/2

》98/20

》 49/10 m

Hence, Radius is 49/10 m

Now we have to find the area

As we know that,

• Area of circle = πr²

where, r is radius

》 πr²

》22/7 × (49/10)²

》22/7 × 49/10 × 49/10

》22/1 × 7/10 × 49/10

》154 × 49 / 100

》7546/100

》75.46 m²

Hence, Area is 75.46 m²

Now we have to find the circumference :

As we know that ,

• Circumference = 2πr

where r is radius

》 2πr

》2 × 22/7 × 49/10

》2 × 22 × 7/10

》44 × 7/10

》30.8m

Hence, Circumference is 30.8m

Answer 2

Given :

• Diameter of a circular garden is 9.8 m.

To Find :

• Area
• Circumference

Solution :

★ Area :

To find area, First we've to find Radius.

$\tt \longrightarrow \: diameter \: = \: 9.8m \\ \\ \tt \longrightarrow \:radius (r)\: = \: \frac{diameter}{2} \\ \\ \tt \longrightarrow \:radius (r)\: = \:\frac{9.8}{2} \\ \\ \tt \longrightarrow \:radius (r)\: = \:\frac{98}{20} \\ \\ \tt \longrightarrow \:radius (r)\: = \:\frac{49}{10}m$

Radius = $\dfrac{49}{10}$

So now we've π = $\dfrac{22}{10} ,r = \dfrac{49}{10}$

By using formula,

$\tt \longrightarrow \: area \: of \: circle \: = \: pi {r}^{2} \\ \\ \tt \longrightarrow \: area \: of \: circle \: = \: \frac{22}{7} \times ({ \frac{49}{10} )}^{2} \\ \\ \tt \longrightarrow \: area \: of \: circle \: = \: \frac{22}{7} \times \frac{49}{10} \times \frac{49}{10} \\ \\ \tt \longrightarrow \: area \: of \: circle \: = \: \frac{22}{1} \times \frac{7}{10} \times \frac{49}{10} \\ \\ \tt \longrightarrow \: area \: of \: circle \: = \: \frac{159 \times 49}{100} \\ \\ \tt \longrightarrow \: area \: of \: circle \: = \: \frac{7546}{100} \\ \\ \tt \longrightarrow \: area \: of \: circle \: = \:75.46 {m}^{2}$

•°• Area = 75.46²

__________________________

★ Circumference :

So now we've π = $\dfrac{22}{10}, r = \dfrac{49}{10}$

By using formula,

$\tt \longrightarrow \: circumference \: = \: 2\pi \\ \\ \tt \longrightarrow \: circumference \: = \:2 \times \frac{22}{7} \times \frac{49}{10} \\ \\ \tt \longrightarrow \: circumference \: = \:2 \times \frac{22}{1} \times \frac{7}{10} \\ \\ \tt \longrightarrow \: circumference \: = \: \frac{2 \times 22 \times 7}{10} \\ \\ \tt \longrightarrow \: circumference \: = \: \frac{308}{10} \\ \\ \tt \longrightarrow \: circumference \: = \:30.8m$

•°• Circumference = 30.8m

________________________

Hence,

• Area = 75.46²
• Circumference = 30.8m