Question

the diameters of two circle are 3.5cm and 6cm find the ratio of the area of the large circle to find that of the smaller circles??

Answer 1

pi×R2/pi×r2
(6/2)2/(3.5/2)2
9/12.25/4
9×4/12.25
36/12.25

Answer 2

Answer: 144:49

Step-by-step explanation:

Given: The diameter of the larger circle D=6cm

Therefore, the radius of the larger circle R=D/2=3 cm

The diameter of the larger circle d= 3.5 cm=7/2 cm

Therefore, the radius of the larger circle r=d/2=7/4cm

The area of the circle with radius(r) is given by:- $\pi\ r^2$

Thus, the ratio of area of the large circle to find that of the smaller circle

$=\frac{\text{area of large circle}}{\text{area of smaller circle}}=\frac{\pi\ (3)^2}{\pi\ (\frac{7}{4})^2}=\frac{9}{\frac{49}{16}}=\frac{144}{49}$

Hence, the ratio of area of the large circle to find that of the smaller circle=144:49