As performed in real lab:
Materials required:
Coloured paper, compass, scale, a pair of scissors, gum, colours
Procedure:
Draw a circle of radius r = 4 cm (say) on the paper.
Divide the circle into 16 equal parts. [Fig (a)]
Cut all the 16 parts and arrange them to get the [Fig (b)].
Take any part from any side and further divide it into 2 parts. [Fig (c)]
To complete the shape of rectangle arrange these two smaller parts at the corners of the shape obtained in [Fig (b)].
Find the length and the breadth of the rectangle so formed [Fig (d)].
Find the area of the rectangle.
Fig (b)
Fig (d)
As performed in Simulator:
Click on scale (between 2 and 3) in workbench to draw circle.
Click on the circle to mark 16 sectorials parts & color them differently.
Move mouse over each wedge to align them in a row.
Click on next button below to color wedges & divide in two group.
Click blue group to rotate and align.
Drag the blue group and drop over green group to join and form parallelogram.
Click on left most wedge to cut it into two parts.
Drag the red part and attach to the right end so as to form a rectangle.
This is a rectangle whose area can be calculated as (Length x Breadth).
Observations:
The students will observe that the rectangle is obtained from parts of circle. Hence area of circle = π x r^{2}
1 videos228 docs21 tests

1. What is the formula for finding the area of a circle? 
2. How can the area of a circle be half the product of its circumference and radius? 
3. Is there a relationship between the area, circumference, and radius of a circle? 
4. How can I find the area of a circle if I know its circumference? 
5. Are there any other formulas to find the area of a circle? 
1 videos228 docs21 tests


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