Question

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A wire is in the shape of a rectangle of length 36 cm and width 30 cm. It is reshaped and bent in the
form of a circle. Find the radius of the circle.
A road roller makes 5000 revolutions in covering 22 km. Find the radius of the roller.​

Answer 1

Step-by-step explanation:

For the first question:

Perimeter of the rectangle = 2(l+b)

l = 36 cm

b = 30 cm

=> 2(36+30)

= 2×66

= 132 cm

therefore, Circumference of a circle = 132 cm

Formula for Circumference = 2 π r

=> 132 = 2 × 22/7 × r

132 × 1/2 × 7/22 = r

r = 7 × 3

r = 21 cm