SOLID GEOMETRIC FIGURES
Geometry
Example:
Calculate the volume and surface area of a rectangular solid with a = 3", b = 4", and
c = 5". Be sure to include units in your answer.
Solution:
V = (a)(b)(c)
SA = 2(ab + ac + bc)
V = (3)(4)(5)
SA = 2[(3)(4) + (3)(5) + (4)(5)]
V = (12)(5)
SA = 2[12 + 15 + 20]
V = 60 cubic inches
SA = 2[47]
SA = 94 square inches
Cube
Figure 15 Cube
A cube is a six-sided solid figure whose faces are congruent
squares, as shown in Figure 15.
The volume of a cube is calculated using the following
formula:
V = a3
(3-13)
The surface area of a cube is calculated using the following
formula:
SA = 6a2
(3-14)
The surface area of a cube is expressed in square units, and the volume of a cube is expressed
in cubic units.
Example:
Calculate the volume and surface area of a cube with a = 3". Be sure to include units
in your answer.
Solution:
V = a3
SA = 6a2
V = (3)(3)(3)
SA = 6(3)(3)
V = 27 cubic inches
SA = 6(9)
SA = 54 square inches
Sphere
A sphere is a solid, all points of which are equidistant from a fixed point, the center, as shown in
Figure 16.
MA-03
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