Question

Length and breadth of a piece of rectangular wire are 18 cm and 15 cm. It is bent into the shape
of a circle. Find the diameter of the circle.
Find the ratio of their circumferences​

Answer 1

Correct Question

Length and breadth of a piece of rectangular wire are 18 cm and 15 cm. It is bent into the shape of a circle. Find the diameter of the circle.

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Given

• Length of rectangular wire ⇒ 18 cm
• Breadth of rectangular wire ⇒ 15 cm
• It is rebent to form a circle.

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To Find

• The diameter of the circle.

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Solution

We'll need to first find the perimeter of the rectangular wire.

Perimeter of Rectangle ⇒ 2 (Lenght + Breadth)

Length ⇒ 18 cm

Breadth ⇒ 15 cm

Perimeter of Rectangular Shaped Wire ⇒ 2 (18+15)

⇒ 2 (33)

⇒ 66 cm

∴ The perimeter of the rectangle is 66 cm

The circumference = Perimeter of the rectangle

Circumference ⇒ 66 cm

To find the diameter of the circle we will solve the following equation.

$\pi d = 66$

Step 1: Simplify the equation.

⇒ $\pi d = 66$

⇒ $\dfrac{22}{7} d = 66$

Step 2: Multiply $\frac{7}{22}$ from both sides of the equation.

⇒ $\dfrac{22}{7} d \times \dfrac{7}{22} = 66\times \dfrac{7}{22}$

⇒ $d = 3\times 7$

⇒ $d = 21$

∴ The diameter of the circle would be 21 cm.

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Answer 2

Answer:

Question to be asked :-

Length and breadth of a piece of rectangular wire are 18 cm and 15 cm. It is bent into the shape of a circle. Find the diameter of the circle.

Given :-

• Length of wire = 18 cm
• Breadth of wire = 15 cm

To Find :-

Diameter of circle

Solution :-

At first we will find Perimeter of rectangle

$\fbox{Perimeter = 2(l + b)}$

$\sf \: Perimeter \: = 2(18 + 15)$

$\sf \: Perimeter = 2(33)$

$\sf \: Perimeter = 66 \: cm$

Now,

Circumference = Perimeter

$\sf \: 66 = \pi \: d$

$\sf \: 66 = \dfrac{22}{7} d$

$\sf \: d = \cancel{ 66 }\times \dfrac{7}{ \cancel{22}}$

$\sf \: d = 3 \times 7$

$\frak \red{d = 21 \: cm}$