Question

3. A wire is in the shape of a rectangle. Its length is 40 cm and breadth is 22 cm. If the
the shape of a square and then into a circle, find: (i) the side of the square
(ii) the radius of the circle.
4. A door of length 2 m and breadth 1 m is fitted in a wall. The length of the wall i​

Answer 1

In the whole shape changes the perimeter of the wire will remain same .

So , Perimeter of rectangle = perimeter of square

2 × ( l + b ) = 4 × side

2 × ( 40 + 22 ) = 4 × side

2 × 62 = 4 × side

124 / 4 = side

31 cm = side of square

Now perimeter of rectangle = perimeter of circle

124 = 2 × 22/7 × radius

124 × 7 / 2 × 22 = radius

62 × 7 / 22 = radius

31 × 7 / 11 = radius

217 / 11 = radius of the circle