rounded to the nearest ounce, jack’s basketball weighs 22

Rounded to the nearest ounce, Jack’s basketball weighs 22 oz. What is the

least and most it could weigh, in tenths of an ounce?

COURSE 1 LESSON 9-3

21.5 oz; 22.4 oz

9-3

Perimeters and Areas of Rectangles

In Lesson 9-2 you learned to convert between metric

measurements.

What You Learned

Introduction

pg 426-430

Pg 134-135 Daily Notetaking Guide

Materials:

Materials

In Lesson 9-3 you will learn to solve problems involving

perimeters and areas of rectangles

What You’ll Learn

Why Learn This?

The length of a fence around a figure is a different

measure from the area enclosed be the fence. You

need to know how to find both measures.

Introduction

Vocabulary

Perimeter – of a figure is the distance around the figure.

Area – of a figure is the number if square units the figure

contains.

Vocabulary

COURSE 1 LESSON 9-3

(For help, go to Lesson 4-2.)

1. Name the base and the exponent in 32.

Perimeters and Areas of Rectangles

9-3

Check Skills You’ll Need

Vocabulary Review

base: 3; exponent: 2

Simplify each expression

2. 42 42 = 4 4 = 16

3. 62 62 = 6 6 = 36

4. 5.42 5.42 = 5.4 5.4 = 29.16

5. 1.62 1.62 = 1.6 1.6 = 2.56

COURSE 1 LESSON 9-3

To renovate their bedroom, the Novaks are

carpeting the floor and pasting a wallpaper border along the

top of each wall. Find the perimeter and area of their

bedroom.

The length is 12 ft.

The width is 14 ft.

P = 2( + w) Use the formula for perimeter.

= 2(12 + 14) Substitute 12 for and 14 for w.

= 2 26 Add.

= 52 Multiply.

Perimeters and Areas of Rectangles

9-3

COURSE 1 LESSON 9-3

(continued)

The perimeter is 52 feet. The area is 168 square feet.

The length is 12 ft.

The width is 14 ft.

A = w Use the formula for area.

= 12 14 Substitute 12 for and 14 for w.

= 168 Multiply.

Perimeters and Areas of Rectangles

9-3

Quick Check

COURSE 1 LESSON 9-3

The perimeter of a square is 28 meters. Find its area.

Use the perimeter formula.

P = 4s

Use the area formula.

A = s2

= 72

= 49

The area of the square is 49 square meters, or 49 m2.

28 = 4s

=

7 = s

28

4

4s

4

Perimeters and Areas of Rectangles

9-3

Quick Check

What is the difference between the area of a figure and

the perimeter of a figure?

The area of a figure is the number of square units it

contains. The perimeter of a figure is the distance

around it.

Closure

9-3

How do you find the area and the perimeter of a

rectangle?

Area: Use the formula A= l x w (Area = Length x Width)

Perimeter: Use the formula P = 2(l + w) [Perimeter = 2 x

(Length + Width)]

Perimeters and Areas of Rectangles

Find the perimeter and area of each.

1. a square with sides that measure 25 mm

2. a rectangle with a length of 11 in. and a width of 8 in.

3. a rectangle with a width of 9 cm and a length of 27 cm

4. a square with a side of 13 ft

COURSE 1 LESSON 9-3

100 mm; 625 mm2

38 in.; 88 in.2

72 cm; 243 cm2

52 ft; 169 ft2

9-3

Class work

pg 429 – 430 1 - 30

Homework

pg 387 Practice 9-3

pg 388 Guided Problem Solving 9-3

Work