Question

please give me answer in this question number 13

Answer 1

first of all find the area of outer circle and then area of inner circle and at a last subtract the inner circle from outer circle

Answer 2

Width of the ring = 3.5 cm

Solution:

Area of the bigger circle = 1886.5 cm²

Area of the circle = $\pi R^{2}$

$\Rightarrow 1886.5=\frac{22}{7} \times R^{2}$

$\Rightarrow 1886.5\times\frac{7}{22} = R^{2}$

$\Rightarrow 600.25= R^{2}$

Switch the sides.

$\Rightarrow R^{2}= 600.25$

Taking square root on both sides of the equation.

R = 24.5 cm

Area of the smaller circle = 1386 cm²

Area of the circle = $\pi r^{2}$

$\Rightarrow 1386=\frac{22}{7} \times r^{2}$

$\Rightarrow 1386\times\frac{7}{22} = r^{2}$

$\Rightarrow 441= r^{2}$

Switch the sides.

$\Rightarrow r^{2}= 441$

Taking square root on both sides of the equation.

r = 21 cm

Width of the ring = R – r

                            = 24.5 – 21

                            = 3.5 cm

Width of the ring = 3.5 cm

To learn more...

https://brainly.in/question/8282951

https://brainly.in/question/11982040