Assess Yourself
How well do you understand the ideas in this lesson?
Goal:
Goal:
Show What You Know!
Are you ready to take this lesson's quiz? These questions will help you find out. Go back to the lesson if you do not know an answer.
Which formula would you use to find the area of a rectangle?
- \({\text{A} = l \div w}\)
- \({\text{A} = l \times w}\)
- \({\text{A} = l + w}\)
- \({\text{A} = l - w}\)
That is not correct. To find the area of a rectangle, multiply the length by the width.
To find the area of a rectangle, multiply the length by the width.
That is not correct. To find the area of a rectangle, multiply the length by the width.
That is not correct. To find the area of a rectangle, multiply the length by the width.
Which math sentence would find the missing length of the rectangle?
- 4 sq. ft. \({=}\) 2 ft. \({+}\) w
- 4 sq. ft. \({=}\) 2 ft. \({-}\) w
- 4 sq. ft. \({=}\) 2 ft. \({\div}\) w
- 4 sq. ft. \({=}\) 2 ft. \({\times}\) w
That is not correct. Remember, if \({\text{A} = l \times w}\), then \({\text{A} \div w = l}\).
That is not correct. Remember, if \({\text{A} = l \times w}\), fill in the clue and solve for the missing width.
That is not correct. Remember, if \({\text{A} = l \times w}\), you can divide and use \({\text{A} \div w = l}\).
Remember, if \({\text{A} = l \times w}\), fill in the clue and solve for the missing width.
What is the missing width?
- 7 ft.
- 2 sq. ft.
- 12 sq. ft.
- 16
Remember, A \({=}\) l \({\times}\) w. So, 14 sq. ft. \({=}\) 2 ft \({\times}\) ? or 14 \({\div}\) 2 \({=}\) 7, or 7 ft.
That is not correct. Remember, A \({=}\) l \({\times}\) w. So, 14 sq. ft. \({=}\) 2 ft \({\times}\) ?. Use a division sentence to solve.
That is not correct. Remember, A \({=}\) l \({\times}\) w. So, 14 sq. ft. \({=}\) 2 ft \({\times}\) ? Think "What times 2 equals 14?".
That is not correct. A \({=}\) l \({\times}\) w. So, use a division sentence that makes you think 14 \({\div}\) 2 = what?
What is the length of the missing width?
- 5 cm
- 5 sq. cm
- 30 cm
- 25 sq. cm
Correct! 25 sq cm \({=}\) 5 cm \({\times}\) 5 cm!
That is not correct. The missing side will not have a sq. cm measurement.
That is not correct. It looks like you added. You need to divide 25 by 5 to find the missing measurement.
That is not correct. This is the area of the rectangle; you need to find the measurement of the missing side.
If the area of a rectangle is 30 sq. cm and the width is 6 cm, what is the length?
- 5 in.
- 5 cm
- 5 sq. cm
- 6
That is not correct. Always be sure to look at the measurement unit to make sure all are the same.
That is correct! 30 sq. cm \({\div}\) 6 cm \({=}\) 5 cm.
That is not correct. Remember, the side measurements aren't in square units. They are just the straight units of measurement.
That is not correct. We know that one side is 6 cm. If the other side were also 6 cm , the area would be 36 sq. cm.
What is the measurement of the missing width?
- 3 in.
- 3 sq. in.
- 9 in.
- 27 sq. in.
That is correct! 27 sq. in. \({=}\) 9 in. \({\times}\) 3 in.
That is not correct. The sides are not measured in square inches; only the total area is square inches.
That is not correct. Think to yourself, What times 9 equals 27?
That is not correct. This is the total area. You need to find the missing measurement for the width.
Which equation can be used to find the missing width of a rectangle with these measurements?
40 sq. m \({=}\) w \({\times}\) 10 m
- 40 sq. m \({\div}\) 10 m \({=}\) w
- 40 sq. m \({\times}\) 10 m \({=}\) w
- 40 sq. m \({-}\) 10 m \({=}\) w
- 40 sq. m \({+}\) 10 m \({=}\) w
Correct! 40 sq. m \({\div}\) 10 \({=}\) w.
That is not correct. You can think, 10 m \({\times}\) what \({=}\) 40 sq m?
That is not correct. Remember the formula, A \({=}\) l \({\times}\) w. You can move numbers around and have A \({\div}\) w \({=}\) l.
That is not correct. You need to either divide or multiply.
If the area of a rectangle is 54 sq. cm and the width is 6 cm, what is the length?
- 9 in.
- 9 cm
- 9 sq. cm
- 6
That is not correct. Remember to always check the measurement unit; all three should be the same.
That is correct! 54 sq. cm \({\div}\) 6 cm \({=}\) 9 cm. The width of the rectangle is 9 cm.
That is not correct. Only the total area has the "sq." label; the sides are just cm.
That is not correct. Think, What times 6 equals 54? You can also divide 54 \({\div}\) 6 \({=}\) 9.
What is the measurement of the missing width?
- 6 in.
- 6 sq. in.
- 7 in.
- 42 sq. in.
Correct! You can think of this as 42 \({\div}\) 7 \({=}\) 6. The missing side is 6 in.
That is not correct. To find the missing side, use the equation for finding Area, A \({=}\) l \({\times}\) w.
That is not correct. To find the missing side, use the equation for finding Area, A \({=}\) l \({\times}\) w.
That is not correct. This is the total area. You need to divide to find the missing side measurement.
Which rectangle has a missing measurement of 8 m?
That is not correct. To find the missing side, use the equation for finding Area, A \({=}\) l \({\times}\) w.
That is not correct. To find the missing side, use the equation for finding Area, A \({=}\) l \({\times}\) w.
That is correct! The missing length is 8 m!
That is not correct. To find the missing side, use the equation for finding Area, A \({=}\) l \({\times}\) w.
Summary
Questions answered correctly:
Questions answered incorrectly: