AREA OF CIRCLE

You are familiar with the plane figure, the circle.

Look at this circle and then review the definitions below.

Pi or π = 3.1416

3.1416 has been rounded

to 3.14 for some of the

problems in this ACCP

Definitions:

A circle is a plane surface bounded by a curved line. Every point on the curved

line is equally distant from the center of the figure.

Diameter: The diameter of a circle is a straight line drawn through the center

from one side to the other. In other words, it is the distance across the circle

through its center, and this distance is the same everywhere.

Radius or Radii: The radius of any circle is a straight line between the circle

and its center. All the radii (plural of radius) of the same circle are of equal

length. Their length is always equal to onehalf of the diameter.

Circumference: The circumference is the curved line that bounds a circle. In

other words, it is the distance around the circle.

Pi, or ___: The Greek letter is used to represent the relation of the

circumference to the diameter of any circle. It has a fixed value for every

circle: The ratio of circumference to diameter equals approximately 3.14.

ircumference__

C

_

= Diameter = 3.14