1. Ratios, Rates and Percents
Lesson 5
Ratios, Rates and Percents
Perimeter and Area

2. Warm-Up Determine whether or not each sequence is a geometric
sequence. Explain your choice.
2, 6, 18, 54, …
2, 4, 6, 8, …
Complete each conversion.
4 yards = _____ feet
20 millimeters = _____ centimeters

3. Target: Convert measurements to find perimeter and area.

4. Vocabulary Perimeter: The distance around a figure.
Area: The number of square units needed to cover a
surface.

6. Example 1
Find the perimeter of the rectangle in: a. meters b. centimeters a. Add lengths of the four sides: b. Convert using 1 meter = 100 centimeters Add lengths of sides:

7. Example 2 Find the area of the triangle in: a. feet b. inches
a. Triangle Area Formula:
b = 4, h = 3 ; Calculate the area
The area is 6 square feet.
b. Convert using 1 foot = 12 inches
Calculate the area:
The area is 864 square inches.

8. Example 3a One rectangle has sides twice as long as another
rectangle. Find the smaller perimeter to the larger
perimeter.
Perimeter of small rectangle: = 8 cm
Perimeter of large rectangle: =16 cm
Ratio of the smaller perimeter
to the larger perimeter:

9. Example 3b One rectangle has sides twice as long as another
rectangle. Find the ratio of the smaller area to the
larger area.
Area of small rectangle: 3 × 1 = 3 square centimeters
Area of large rectangle : 6 × 2 = 12 square centimeters
Ratio of smaller area to
the larger area:

10. Exit Problems Find the perimeter of the rectangle in yards.
2 yd
4 yd
Find the perimeter of the rectangle in yards.
Find the perimeter of the rectangle in feet.
Find the area of the rectangle in square yards.
Find the area of the rectangle in square feet.

11. Communication Prompt
For a square that is 1 centimeter by 1 centimeter, how do
you find
its perimeter in terms of millimeters?
its area in terms of square millimeters?