Geometry
SOLID GEOMETRIC FIGURES
The volume of a sphere is calculated using the following
Figure 16 Sphere
formula:
V =4/3pr3
(3-15)
The surface area of a sphere is calculated using the
following formula:
SA = 4pr2
(3-16)
The surface area of a sphere is expressed in square units,
and the volume of a sphere is expressed in cubic units.
Example:
Calculate the volume and surface area of a sphere with r = 4". Be sure to include units
in your answer.
Solution:
V = 4/3pr3
SA = 4pr2
V = 4/3p(4)(4)(4)
SA = 4p(4)(4)
V = 4.2(64)
SA = 12.6(16)
V = 268.8 cubic inches
SA = 201.6 square inches
Right Circular Cone
Figure 17 Right Circular Cone
A right circular cone is a cone whose axis is a line
segment joining the vertex to the midpoint of the circular
base, as shown in Figure 17.
The volume of a right circular cone is calculated using
the following formula:
V = 1/3pr2h
(3-17)
The surface area of a right circular cone is calculated
using the following formula:
SA = pr2 + prl
(3-18)
The surface area of a right circular cone is expressed in square units, and the volume of a right
circular cone is expressed in cubic units.
Rev. 0
Page 15
MA-03
