Question

A wire in the shape of a rectangle of length 18 cm and width 15 cm is reshaped and bent in the form of a circle. Find the radius of the circle.(Take = /)

Answer 1

total perimeter of the rectangle = 2(15+28)

= 2(33)

= 66

so perimeter of the circle = 66

perimeter of a circle = 2πr

so 2πr = 66

πr = 33

22/7r = 33

2/7r = 3

r = 3×7/2

r = 21/2

r = 10.5

so the radious is 10.5

Answer 2

Given :

• Length of wire is 18 cm .
• Width of wire is 15 cm .

To Find :

• Radius of circle if the same wire is bent in the form of a circle.

Solution :

Firstly we will find the Perimeter of Rectangle :

Using Formula :

$\longmapsto\tt\boxed{Perimeter\:of\:Rectangle=2(l+w)}$

Putting Values :

$\longmapsto\tt{2(18+15)}$

$\longmapsto\tt{2(33)}$

$\longmapsto\tt\bf{66\:cm}$

Now ,

The same wire is bent in the form of a circle . So ,

Using Formula :

$\longmapsto\tt\boxed{Circumference\:of\:Circle=2\pi{r}}$

Putting Values :

$\longmapsto\tt{66=2\times\dfrac{22}{7}\times{r}}$

$\longmapsto\tt{66\times{7}=44\times{r}}$

$\longmapsto\tt{462=44\:r}$

$\longmapsto\tt{r=\cancel\dfrac{462}{44}}$

$\longmapsto\tt\bf{r=10.5}$

So , The Radius of Circle is 10.5 cm .