Wednesday, April 16, 2008

Angel's Scribe Post

Cylinders and Circles
Today in class we learned about the circles and its radius, diametre, and circumferance. Later on during class we also learned how to find the area of a cylinder.
All about the radius and diameter : In class we were told that radius is the distance from the centre of the circle to the edge and you can get it by dividing the diameter because the diameter is double the distance of a radius going from one edge of the circle to the other. The formula to get the diameter : d=2r. meaning the diameter = 2x the radius.

The circumference : The circumference is the distance around a circle. You can get this by 2Pi r (2 x pi x r) pi 2r or pi x diameter.

Cylinder : In class we learned how to make a net of a cylinder.
also make sure that the circles are the same size.

L = Circumference
W = Height

A = Pi R2 C = Pi D
A = 3.14 x 5cm2 C = 3.14 x ??cm
A = 3.14 x ??cm C = 3.14
A = ??cm2

Total surface Area : ??cm2+??cm2+??cm2 = ??cm2

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