Concentric circles :
In this section, we are going to learn about Concentric circles.
Already we are familiar with Circles.
When a small stone was dropped in still water, you might have seen circular ripples were formed. Which is the center of these circles ?
Is it not the place where the stone was dropped ?
The circles with different measures of radii and with the same center are called concentric-circles. The center is known as common center.
Circles drawn in a plane with a common center and different radii are called concentric-circles. See the figure given below.
Look at the following two figures :
The above figure represents two concentric-circles.
In the above figure, the area between the two concentric -circles are shaded with red color.
The red colored area is known as circular ring.
In the figure given above, C₁ and C₂ are two circles having the same center O with different radii r₁ and r₂ respectively.
Circles C₁ and C₂ are called concentric-circles.
The area bounded between the two circles is known as circular ring.
Width of the circular ring = OB – OA = r₂ - r₁ ( r₂ > r₁)
Draw concentric-circles with radii 3 cm and 5 cm and shade the circular ring.
Find its width.
Given: The radii are 3 cm and 5 cm.
Steps for construction :
Step 1 :
Draw a rough diagram and mark the given measurements.
Step 2 :
Take any point O and mark it as the center.
Step 3 :
With O as center and draw a circle of radius OA = 3 cm
Step 4 :
With O as center and draw a circle of radius OB = 5 cm.
Thus the concentric-circles C₁ and C₂ are drawn.
Width of the circular ring = OB – OA
Width of the circular ring = 5 – 3
Width of the circular ring = 2 cm.
After having gone through the stuff given above, we hope that the students would have understood "Concentric-circles".
Apart from the stuff given above, if you want to know more about "Concentric-circles", please click here
Apart from the stuff given on this web page, if you need any other stuff in math, please use our google custom search here.
APTITUDE TESTS ONLINE
ACT MATH ONLINE TEST
TRANSFORMATIONS OF FUNCTIONS
ORDER OF OPERATIONS
MATH FOR KIDS
HCF and LCM word problems
Converting repeating decimals in to fractions