This handy Spectrum Math Grade 7 Answer Key Chapter 5 Lesson 5.9 Area: Rectangles provides detailed answers for the workbook questions
Spectrum Math Grade 7 Chapter 5 Lesson 5.9 Area: Rectangles Answers Key
The area of a figure is the number of square units inside that figure. Area is expressed in square units or units2.
The area of a rectangle s the product of its length and its width.
A = l × w
A = 5 × 10 = 50 cm2
A = 5 × 5
A = 5 × 5 or 52
A = 25 cm2
If you know the area of a rectangle and either its length or its width, you can determine the unknown measure.
A = l × w
24 = 6 × w
\(\frac{24}{6}\) = \(\frac{6w}{6}\)
4 = w
The width is 4 meters.
Find the unknown measure for each rectangle.
Question 1.
a.
area = ______________ cm2
Answer:
A = 54 cm2
Explanation:
The area of a rectangle s the product of its length and its width.
A = l × w
Given,
l = 6cm, w = 9cm
A = 6 × 9
A = 54 cm2
b.
area = _____________ m2
Answer:
A = 84 m2
Explanation:
The area of a rectangle s the product of its length and its width.
A = l × w
Given,
l = 8m, w = 10.5m
A = 8 × 10.5
A = 84 m2
c.
area = ______________ in.2
Answer:
A = 56.25 in2
Explanation:
The area of a square is the product of its sides.
A = s x s
Given,
side = 7.5 in
A = 7.5 x 7.5
A = 56.25 in2
Question 2.
a.
length = _______________ ft.
Answer:
length = 15 ft.
Explanation:
The area of a rectangle s the product of its length and its width.
A = l × w
Given,
A = 150 ft2, l = 10 ft
150 = 10 × w
w = \(\frac{150}{10}\)
A = 15 ft
b.
width = _______________ m
Answer:
width = 6 m
Explanation:
The area of a rectangle s the product of its length and its width.
A = l × w
Given,
A = 72 m2, w = 12 m
72 = l × 12
l = \(\frac{72}{12}\)
l = 6m
c.
area = _______________ in.2
Answer:
area = 135 in.2
Explanation:
The area of a rectangle s the product of its length and its width.
A = l × w
Given,
l = 9 in, w = 15 in
A = 9 × 15
A = 135 in.2
Question 3.
a.
area = _____________ in.2
Answer:
area = 165 in.2
Explanation:
The area of a rectangle s the product of its length and its width.
A = l × w
Given,
l = 16.5 in, w = 10 in
A = 16.5 × 10
A = 165 in.2
b.
length = ______________ ft.
Answer:
length = 12.5 ft.
Explanation:
The area of a rectangle s the product of its length and its width.
A = l × w
Given,
A = 62.5 ft2, w = 5 ft
62.5 = l × 5
l = \(\frac{62.5}{5}\)
l = 12.5 ft.
c.
side = ______________ m
Answer:
side = 11 m
Explanation:
The area of a square is the product of its sides.
A = s x s
Given,
A = 121 m2,
121 = s2
s2 = 121
s = 11 m.