MTH 232
Section 10.2
Area and Perimeter
Area
• The number of square units required to cover
a region.
• Area is measured in square units (ft2, cm2, in2)
Perimeter
• The distance around a region (found by adding
up the lengths of the sides of the polygon).
• Perimeter is measured in regular (nonsquared) units.
Circles
• Because circles don’t have sides, the
geometric equivalent of perimeter is
circumference:
More About Circles
• Circles, however, do have area. The definition
of area for a circle is the same as the
definition of area for a polygon, despite the
fact that it is hard to visualize filling a circle
with “square units”
About Pi
• Pi is a greek letter that is used to represent the
ratio of the circumference of a circle to its
diameter:
Composite Areas