Question

Calculate the cost of putting up
One circle has a radius of 98 cm and a second concentric circle has a radius of 1m26cm.
How much longer is the circumference of the second circle than that of the first?​

Answer 1

Answer:

Ist Circle.circumference

= 2πx98=196πcm

2nd circle circumference

= 2 πr=2xπx126=252πcm

difference in length of Oce

=252π-196π = 56πcm

= 175.8cm. Ans

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.