3.3 , Geometry
The figure above is a right circular cylinder. The two bases are circles of the same size with centers O and
P, respectively, and altitude (height)研is perpendicular to the bases. The surface area of a right
circular cylinder with a base of radius rand height加s equal to 2(正） + 2 冗rh (the sum of the areas of
the two bases plus the area of the curved surface).
The volume of a cylinder is equal to冗产h, that is,
(area of base) x (height).
In the cylinder above, the surface area is equal to
2 ( 25 冗） +^2 冗( 5 )( 8 ) = 130兀，
and the volume is equal to
25 冗(8) = 200兀
- Coordinate Geometry
II
y3
21
I
-4 -3 -2 -1 0
1 2 3 4 X
III - 2
IV
The figure above shows the (rectangular) coordinate plane. The horizontal line is called the x-axis and
the perpendicular vertical line is called the y-axis. The point at w阮h these two axes intersect,
designated 0, is called the origin. The axes divide the plane into four quadrants, I, II, III, and IV, as
shown.
