Upcoming SlideShare
×

Area of a Circle

358 views

Published on

Published in: Education, Technology
0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total views
358
On SlideShare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
8
0
Likes
0
Embeds 0
No embeds

No notes for slide

Area of a Circle

1. 1. A circle is a 2-dimensional shape which made by drawing a curve that has always the same distance from the center. It is one of the basic shape in geometry
2. 2. Circumference: The distance around the circle; a special name for the perimeter of a circle  Arc: A part of the circumference  Radius: The distance from the centre to the circumference  Diameter: the distance from side to side passing though the centre; the greatest with of a circle 
3. 3. The formula: A = π × r2 Π= *It is very important to know either the Radius or the Diameter in order to take out the area of a circle*
4. 4. Ex 1 Ex 2 r=4cm d=6cm So, r=3cm A = π × r2 A= x 42 A = π × r2 A= A= x 32 x 16 ~ 5.28 A= x 9 ~ 28.28
5. 5. To find an area of an Irregular shape, Separate each shape to find its area Example A sports ground Rectangle A=wxh, so 60×40=2400m2 Circle d=40m, so r=20m A=πr2=π×202=400π=1256m2 Irregular Shape 2400m2+1256m2=3656m2 40m 60m 40m Note π=3.14 d÷2=r A=πr2=πxr2 A=wh=wxh 40m 60m
6. 6. Thank you