Homework Help: Maths

Posted by Math's Noob on Sunday, January 8, 2012 at 4:39pm.

The radii of three concentric circles are 2cm, 3cm and 4cm
Find the ratio of the shaded areas A (the second circle from the inside) and B(the outer circle)
(Hint: don't substitute for pi)

Maths - Steve, Sunday, January 8, 2012 at 4:50pm
I assume
A is the area between the 2-cm and the 3-cm circles
B is the area between the 3-cm and 4-cm circles.

A = pi(3^2 - 2^2) = 5pi
B = pi(4^2 - 3^2) = 7pi

B/A = 7/5

Answer this Question

Related Questions

Math - A Target consists of three concentric circles with the same center. The ...
math - The ratio of the radii of two circles is 2:3. find the ratio of their ...
math - The ratio of the radii of two circles is 2:3. Find the ratio of their ...
math - the radii of three concentric circles shown are in the ratio 1:2:3. What ...
maths - there are two circles touching each other at one point. The radius of ...
Math - When the waiter was asked to slice the 16-inch (in diameter) pizza into ...
maths - AB=36 cm and M is the mid-point of AB. Semicircles are drawn on AB,AM ...
math - Two circles with radii 3cm and r cm touch each other externally. If their...
6th grade - tHE AREA OF A RECTANGLE IS 24CM2 IF THE LENGTH OF THE SIDES ARE ...
physics - Two conductors are made of the same material and have the same length...

For Further Reading

First Name:
School Subject:
Answer: