Question

One circle has a radius of 98 cm and a second concentric circle has a radius of 1 m 26 cm.How much longer is the circumference of the second circle than that of the first?

Answer 1

Hey friend..!! here's your answer
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1 meter = 100 cm

Radius of 1st circle = 98 cm
Radius of second circle = 1m 26 cm ( 126 cm)

Circumference of Circle = 2πr

Circumference of 1st circle =
$(2 \times \frac{22}{7} \times 98)cm \\ \\( 2 \times 22 \times 14 )cm\\ \\ 616cm$

Circumference of Second circle =
$(2 \times \frac{22}{7} \times 126)cm \\ \\ (2 \times 22 \times 18)cm \\ \\ 792cm$

We need to find that how much circumference of second circle is greater than smaller one ,

So ,
(792 - 616)cm
=176 cm


Answer : 176 cm

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#Hope its help

Answer 2

Given:-One circle has a radius of 98 cm and a second concentric circle has a radius of 1 m26 cm or 126cm

To find out:-How much longer is the circumference of the second circle than that of first?

Solution:-

Let the radius of outer circle be r1 and inner circle be r2 .

CIRCUMFERENCE of inner circle = 2πr1

=>2×22/7×98

=>616 cm

CIRCUMFERENCE of outer circle = 2πr2

=>2×22/7×126

=>792 cm

DIFFERENCE of outer circle and inner circle

=>792-616=176 cm

circumference of the second circle is 176 cm longer than that of first.