Question

the diameter of the larger circle is 12.5 cm. The diameter of the smaller circle is 8.5 cm. what is the approximate area of the shaded region.
PLZZZ HELP

Answer 1

Answer:

$A=65.97\ cm^2$

Step-by-step explanation:

The complete question is

The shaded region is the area outside the smaller circle and inside the larger circle

we know that

The area of the shaded region is equal to subtract the area of the smaller circle from the area of the larger circle

The area of the circle is equal to

$A=\pi r^{2}$

so

The area of the shaded region is

$A=\pi [r_1^2-r_2^2]$

where

$r_1=12.5/2=6.25\ cm$ ---> radius of the larger circle (is half the diameter)

$r_2=8.5/2=4.25\ cm$ ---> radius of the smaller circle (is half the diameter)

assume

$\pi =3.1416$

substitute

$A=3.1416[(6.25)^2-(4.25)^2]$

$A=65.97\ cm^2$