Rounded to the nearest ounce, Jack’s basketball weighs 22 ...
Transcript of 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