LESSON
7-1 Ratio and Proportion
Examples:
a. The ratio of the angle measures in a quadrilateral is
1:4:5:6. Find each angle measure.
b. The Titanic was 882 feet 9 inches long. You can
build a model of the ship that is 2 feet 6 inches
long and 6 inches high. What was the approximate
height of the Titanic to the nearest inch?
1. The ratio of the side lengths in a rectangle is
5:2:5:2, and its area is 90 square feet. Find the side
lengths.
2. For part of her homework, Celia measured the
angles and lengths of the sides of two triangles.
She wrote down the ratios for angle measures and
side lengths. Two of the ratios were 4:7:8 and
3:8:13. When Celia got to school the next day, she
couldn’t remember which ratio was for angles and
which was for sides. Tell which must be the ratio
of the lengths of the sides. Explain your answer.
3. For a certain type of tropical fish, it is
recommended that you have no more than 2 fish
per 10 gallons of water. How many fish could you
have in a fish tank that holds 35 gallons of water?
4. A library is being
expanded, and the new
wing’s length is to be 50
feet greater than its
width. A diagram of the
new wing is shown. What
are the actual dimensions
of the new wing?
5. The aspect ratio, or ratio
of length to width of the
viewing area, of a widescreen 42-inch television
is 16:9. What are the
dimensions of the
rectangular viewing area
to the nearest tenth?
6. In a museum gift shop, a miniature
Acrocanthosaurus is 22.8 centimeters long and
15.9 centimeters tall. The package says that the
actual dinosaur was approximately 9 meters long.
About how tall was the dinosaur?
7. A model airplane has a wingspan of about 15
inches. The actual airplane has a wingspan of 30
feet and length of 42 feet. How long is the model?
8. The ratio of the interior angle measures of a
pentagon is 2:2:3:4:6. What is the measure of the
smallest angle to the nearest degree?
A. 6.3 m
C. 12.9 m
B. 7.7 m
D. 40.3 m
A. 11 in
C. 21 in
A. 32°
C. 95°
B. 14 in
D. 30 in
B. 64°
D. 191°
9.
10. The ratio of a model scale die cast motorcycle is
1:18. The model is 5¼ inches long. What is the
length of the actual motorcycle in feet and inches?
11.
12. Rectangle A has side lengths 16.4 centimeters and
10.8 centimeters. Rectangle B has side lengths
10.25 centimeters and 6.75 centimeters. Determine
whether the rectangles are similar. If so, write the
similarity ratio.
12. A pet store has various sizes of guinea pig cages. 13. A gymnasium is 96 feet long and 75 feet wide. On
A diagram of the top view of one of the cages is
a blueprint, the gymnasium is 5.5 inches long. To
shown. What are possible dimensions of this
the nearest tenth of an inch, what is the width of
cage?
the gymnasium on the blueprint?
A. 3.6
C. 19
B. 5.5
D. 33
A. 3.7 in
C. 7.0 in
B. 4.3 in
D. 13.6 in
15. ABC has side lengths 14, 8, and 10.4. What are
possible side lengths of DEF if ABC DEF?
14.
A. 3.6
C. 19
B. 5.5
D. 33
A. 28, 20, 20.8
C. 28, 20, 26
B. 35, 16, 20.8
D. 35, 20, 26