Circles area

Download Circles area

Post on 26-Jun-2015

52 views

Category:

Documents

0 download

Embed Size (px)

DESCRIPTION

Animations work when downloaded

TRANSCRIPT

  • 1. October 4, 2012 Circles2. The area of a circle. Next

2. Explanation October 4, 2012Here is a circle.You can divide it into sectors.The sectors can be rearranged, to form a shape veryclose to a rectangle.The two long edges are made up from the circumference,which is dOne side is made up from d 2 which is rEach of the short sides is made up from the radius.The area can now be calculated as r r or r r rMoreNext 3. Example October 4, 2012The second hand on a clock is 11cm long.What is the area of the clock face itpasses over in one minute? A = r A = 11 A = 121 A = 380.1327The area the second hand covers is is 380cm , to 3 s.f.In this case, it is sensible to give an answer to thenearest cm .MoreNext 4. Example October 4, 2012A circular office carpet has a diameter of 1.8m.Calculate its area.A = r Calculate the radius. r = 1.8 2 = 0.9A = 0.9 A = 0.81 A = 2.54690 The carpet is 2.54m , to 2 d.p. It is sensible to give an answer to the nearest cm. More Next End

Recommended

View more >