Question

the area of a circular tin plate is 38.5m².find its circumference. ​

Answer 1

AnswEr :-

• Circumference of the circular tin plate is 22m.

Given :-

• The area of a circular tin plate is 38.5m².

To Find :-

• Circumference of the circular tin plate.

SoluTion :-

As we know that the area of a circle is πr².

Here,

• Area of the circle is 38.5m².

According to question :-

• πr² = 38.5

→ 22/7 r² = 38.5

→ r² = 38.5 × 7/22

→ r² = 12.25

→ r = 3.5m

Formula of the circumference of a circle is 2πr.

Now,

• Circumference = 2πr

→ Circumference = 2 × 22/7 × 3.5

→ Circumference = 2 × 22 × 0.5

→ Circumference = 22m

Hence, the circumference of the circular tin plate is 22m.

Answer 2

Given:-

• Area of the circular tin plate is 38.5m².

To find:-

• The circumference

Solution:-

⟶ Let the radius of the tin be r meters.

⟶ Then it's area is = (πr²) m².

⟶ πr² = 38.5 = $\sf\dfrac{22}{7}$ × r² = 38.5

⟶ r² = [ 38.5 × $\sf\dfrac{7}{22}$ ] = (3.5 × 3.5)

$⟶ r = \sqrt{3.5 \times 3.5} = 3.5$

★Circumference of the plate = 2πr

$⟶ (2 \times \frac{22}{7} \times 3.5)m = 22m$

Therefore, the circumference of the plate is 22m. ___________________________________