9.9 Volume 801REVIEW
- Write as a percent.
- Write as a percent.
- Write 0.827 as a percent.
- Write 0.036 as a percent.
- UNIT COSTS A 24-ounce package of green beans
sells for $1.29. Give the unit cost in cents per ounce.
78109- MILEAGE One car went 1,235 miles on 51.3 gallons
of gasoline, and another went 1,456 on 55.78 gallons.
Which car got the better gas mileage? - How many sides does a pentagon have?
- What is the sum of the measures of the angles of a
triangle?
SECTION 9.9
Volume
We have studied ways to calculate the perimeter and the area of two-dimensional
figures that lie in a plane, such as rectangles, triangles, and circles. Now we will consider
three-dimensional figures that occupy space, such as rectangular solids, cylinders, and
spheres. In this section, we will introduce the vocabulary associated with these figures
as well as the formulas that are used to find their volume. Volumes are measured in
cubic units, such as cubic feet, cubic yards, or cubic centimeters. For example,
- We measure the capacity of a refrigerator in cubic feet.
- We buy gravel or topsoil by the cubic yard.
- We often measure amounts of medicine in cubic centimeters.
Objectives
1 Find the volume of rectangular
solids, prisms, and pyramids.
2 Find the volume of cylinders,
cones, and spheres.1 Find the volume of rectangular solids, prisms, and pyramids.
The volumeof a three-dimensional figure is a measure of its capacity. The following
illustration shows two common units of volume: cubic inches, written as in.^3 , and cubic
centimeters, written as cm^3.
1 in.1 in.1 in.1 cubic inch: 1 in.^31 cm
1 cm1 cm1 cubic centimeter: 1 cm^3The volume of a figure can be thought of as the number of cubic units that will fit
within its boundaries. If we divide the figure shown in black below into cubes, each
cube represents a volume of 1 cm^3. Because there are 2 levels with 12 cubes on each
level, the volume of the prism is 24 cm^3.
1 cm^34 cm3 cm2 cm