Question

Find the area of a circle whose radius is 3 cm ?​

Answer 1

AnswEr:-

Given:-

• Radius of a circle = 3 cm.

To Find:-

• The area of that circle.

Formula Used:-

$\tt\rightarrow Area\:\: of \:\:circle = \pi {r}^2$

Where,

• $\pi$ = 3.14
• r = Radius.

Therefore area of given circle,

$\\ \tt = \pi {r}^{2} \\ \\ \tt = 3.14 \times (3 \: cm) {}^{2} \\ \\ \tt = 3.14 \times 3 \: cm \times 3 \: cm \\ \\ \tt = 3.14 \times 9 \: cm {}^{2} \\ \\ \tt = 28.26 \: cm {}^{2} .$

$\therefore$ The Area of the circle is 28.26 cm².

$\rule{200}2$

More formulas related surface area of volumes:-

• Circumference of circle = $\tt2\pi r.$

• Volume of cube

= Side³

• T.S.A. of cube

= 6 × Side.

• C.S.A. of cube

= 4 × Side.

• Volume of cuboid

= L×B×H.

• T.S.A. of cuboid

= 2(LB+BH+HL).

• C.S.A. of cuboid

= 2(L+B)H.

Where,

• L = Length.
• B = Breadth.
• H = Height.
• $\pi$ = 3.14 or $\dfrac{22}{7}$

• T.S.A. = Total Surface Area.
• C.S.A. = Curved Surface Area.

$\rule{200}2$

Answer 2

Step-by-step explanation:

AnswEr:-

Given:-

Radius of a circle = 3 cm.

To Find:-

The area of that circle.

Formula Used:-

\tt\rightarrow Area\:\: of \:\:circle = \pi {r}^2→Areaofcircle=πr

2

Where,

\piπ = 3.14

r = Radius.

Therefore area of given circle,

\begin{gathered} \\ \tt = \pi {r}^{2} \\ \\ \tt = 3.14 \times (3 \: cm) {}^{2} \\ \\ \tt = 3.14 \times 3 \: cm \times 3 \: cm \\ \\ \tt = 3.14 \times 9 \: cm {}^{2} \\ \\ \tt = 28.26 \: cm {}^{2} . \\ \end{gathered}

=πr

2

=3.14×(3cm)

2

=3.14×3cm×3cm

=3.14×9cm

2

=28.26cm

2

.

\therefore∴ The Area of the circle is 28.26 cm².

\rule{200}2

More formulas related surface area of volumes:-

• Circumference of circle = \tt2\pi r.2πr.

• Volume of cube

= Side³

• T.S.A. of cube

= 6 × Side.

• C.S.A. of cube

= 4 × Side.

• Volume of cuboid

= L×B×H.

• T.S.A. of cuboid

= 2(LB+BH+HL).

• C.S.A. of cuboid

= 2(L+B)H.

Where,

L = Length.

B = Breadth.

H = Height.

\piπ = 3.14 or \dfrac{22}{7}

7

22

T.S.A. = Total Surface Area.

C.S.A. = Curved Surface Area.

\rule{200}2