Area of Circle
Introduction
Area of circle is π times radius square which is written : A= π r² where,A= Area of circle and
r= radius of circle and π =Division of circumference and diameter ( π = 3.14159.......).
Objectives
- Students will be able to find the area of circle then explore the visual experience about it,
Applet
Guideline
- To see the result click on the start button
- To stop click on stop button and watch deeply.
Test your outstanding
Area of circle is equal to the area of ................, .
To construct area of circle by using following protocol.
- create slider (n,4,500,1),
- create slider (r,1,3),
- Take point A,
- Create a circle with radius 6cm and and center A,
- Create point B on the circumference,
- Input :Rotate(B, (360°) / n, A),
- join B and B',
- Make midpoint C of line BB',
- Join A and C,
- Rename the line BB' to dxand AC to dy,
- Input:
- L1: Sequence(Rotate(B, j (360°) / n, A), j, 0, n) ,
- L2:Sequence(CircularSector(A, Element(L1, j), Element(L1, j + 1)), j, 1, n, 2),
- L3:Sequence(CircularSector(A, Element(L1, j), Element(L1, j + 1)), j, 2, n, 2) ,
- L4:Sequence(CircularSector((j dx + fdx/ 2, dy), (j dx+ 0, 0), (j dx+ dx, 0)), j, 0, n / 2 - 1),
- L5:Sequence(CircularSector((j dx, 0), (j dx + dx/ 2, dy), (j dx+ (-dx) / 2, dy)), j, 1, n / 2)
- Finally colour and design to the applet for good vidilazation.