Question

The radius of a circle is 80m and the radius of another concentric
circle is 94m. How much larger is the circumference of second
circle than the circumference of the first circle.​

Answer 1

$\huge\mathbb{SOLUTION:-}$

• Given two concentric circles whose radius are 80 and 94m

• find the circumference of both circles

$\boxed{\sf{Circumference\:of\:circle=2\pi r}}$

• Now :-Circumference of small circle

$\sf\implies Circumference=2\pi r\\ \\ \sf\implies Circumference\:of\: circle_1=2\times \dfrac{22}{7}\times 80\\ \\ \sf\implies Circumference\:of\:circle_1= \dfrac{3520}{7}m{}^{2}$

• Now the circumference of larger circle

$\sf\implies Circumference=2\pi r\\ \\ \sf\implies Circumference\:of\: circle_1=2\times \dfrac{22}{7}\times 94\\ \\ \sf\implies Circumference\:of\:circle_1= \dfrac{4136}{7}m{}^{2}$

• we have to find how much the circumference of larger circle is greater than smaller circle

$\boxed{\sf{Difference\:in\:both\: circles \implies Circumference\:of\: circle_2-Circumference\:of\: circle_1}}$

$\sf\leadsto Difference= \dfrac{4136}{7}-\dfrac{3520}{7}\\ \\ \sf\implies Difference=\dfrac{616}{7}\\ \\ \sf\implies Difference=88m{}^{2}$

$\boxed {\sf{Larger \:circle \:is\: greater\: than\: by\: 88m{}^{2}}}$

Answer 2

Given:-One circle has a radius of 80 cm and a second concentric circle has a radius of 94 cm.

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

=>2×22/7×80

=>3520/7 cm

CIRCUMFERENCE of outer circle = 2πr2

=>2×22/7×94

=>4136/7 cm

DIFFERENCE of outer circle and inner circle

=>4136/7-3520/7=616/7 cm=88 cm

circumference of the second circle is 88 cm longer than that of first.