-From this applet , we show area of circle by dynamic figure.[br]-In this applet at first we draw a circle and it divides many pics like triangle.[br] if you move slider n, then the circle divided into many pics like a triangle and it arranged itself a Rectangle.[br]-where circumference of circle arranged in length and the radios of circle arranged in breadth.[br]so, the area of circle is=Area of Rectangle[br] =length *Breadth[br] =Pi r*r[br] =Pi r^2.

Design an applet to show Area of Circle .

1) Move the slider r then you see circle with different radius.[br]2)Move the slider n then you see a circle divided into many parts like triangle and also you see the arranged rectangle which is made from the many pics of triangle.[br]3)This arranged rectangle gives the area of circle . [br]Where, Pi r=Circumference of circle =Length of Rectangle[br] r=Radius of circle =Breadth of rectangle [br] so, area of Circle =Area of Rectangle [br] =length*bredth[br] =Pi r*r[br] =Pi r^2

1. Open a new GoeGebra window.[br]2.Create a number slider r by using slider tool.(max-4,min 1 and increment 1)[br]3. Again create a number slider n by using slider tool where, min -4, max-60 or you can put any number.[br]4.Draw point A in +y-Axesby using point tool.[br]5.create a circle through center point A and radius r.( if you move slider r then there becomes circle with different Radius.)[br]6.Create a point B in anywhere of the circumference of circle.[br]7.Input Rotate(B,360/n,A) by input tool which gives B'[br]8 Join line segment BB'. by segment tool.[br]9.Draw mid point between the line segment BB' named it by C.[br]10. join line segment AC by segment tool.[br]11.Rename the segment BC by dx and Ac by dy.[br]12. Input L1: Sequence (Rotate(B,j 360/n,A),j,0,n)[br] L2: Sequence(Circular sector(A,Element(L1,j),Element(L1,j+1),j,1,n,2)[br] L3=Sequence (Circular sector(A,Element(L1,j),Element(L1,j+1),j,2,n,2)[br] L4=Sequence (Circular sector ((j dx,0),jdx+dx/2,dy),(jdx+(-dx)/2,dy)),j,1,n/2-1)[br] L5=Sequence(Circular sector((j dx+dx/2,dy),(j dx+0,0),jdx+dx,0)),j,0,n/2-1)[br]13.Hide the objects dx,dy and C.[br]14.color the object L3 and L4 by same color and object L4 and L5 by same color.(by object properties.)[br]15.insert the dynamic text Pi r on the length of rectangle and insert the dynamic text r for breadth of rectangle and decorate it by using object properties .[br]17 insert dynamic text Area of circle = pi r*r[br] = Pi r^2.[br]At last save your ggb file [br]