ANSWERS: (1) diameter
(2) radius
(3) circumference
(4) d
(5) a
(6) b
(7) c
Make sure you understand these terms before going on.
THE GREEK LETTER
Just what does pi, or π, mean and where does it come from? You should understand
why you will use in solving areaofcircle problems.
π = 3.14
You already know from the definitions that π is the ratio of the circumference
to the diameter of a circle.
Ratio
Circumference__ = π = 3.14
Diameter
Look at the circle above. Take your pencil and measure off the length of the
diameter. Then, keeping the length of the diameter on your pencil, start at any
point on the circumference and imagine that you can wrap the pencil around the
circle. (You can see that this has been done on the circle above.) You should
discover that the length of the diameter will divide into the length of the
circumference a little more than three times. To be exact, 3.14 times. (This is a
little easier if done with a can and a piece of string.)
19
Previous Page
