Apply Rectangle Area and Perimeter Formulas - 4th Grade Math
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Find the length of a rectangle with area $A = 54$ and width $w = 6$.
Find the length of a rectangle with area $A = 54$ and width $w = 6$.
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$9$. Use $l = \frac{A}{w} = \frac{54}{6} = 9$.
$9$. Use $l = \frac{A}{w} = \frac{54}{6} = 9$.
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Identify the correct unit for area: inches, square inches, or inches per side.
Identify the correct unit for area: inches, square inches, or inches per side.
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square inches. Area measures surface in square units.
square inches. Area measures surface in square units.
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Identify the correct unit for perimeter: square feet or feet.
Identify the correct unit for perimeter: square feet or feet.
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feet. Perimeter measures distance in linear units.
feet. Perimeter measures distance in linear units.
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A rectangular rug is $12$ ft by $3$ ft. What is its area?
A rectangular rug is $12$ ft by $3$ ft. What is its area?
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$36$ square feet. Apply area formula: $12 \times 3 = 36$ square feet.
$36$ square feet. Apply area formula: $12 \times 3 = 36$ square feet.
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A rectangular garden is $7$ m by $2$ m. What is its perimeter?
A rectangular garden is $7$ m by $2$ m. What is its perimeter?
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$18$ meters. Apply perimeter formula: $2(7) + 2(2) = 18$ meters.
$18$ meters. Apply perimeter formula: $2(7) + 2(2) = 18$ meters.
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A room has area $96$ ft$^2$ and length $12$ ft. What is the width?
A room has area $96$ ft$^2$ and length $12$ ft. What is the width?
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$8$ ft. Rearrange $A = l \times w$: $96 \div 12 = 8$ ft.
$8$ ft. Rearrange $A = l \times w$: $96 \div 12 = 8$ ft.
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A rectangle has perimeter $50$ cm and length $15$ cm. What is the width?
A rectangle has perimeter $50$ cm and length $15$ cm. What is the width?
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$10$ cm. From $P = 2l + 2w$: $50 = 2(15) + 2w$, so $w = 10$.
$10$ cm. From $P = 2l + 2w$: $50 = 2(15) + 2w$, so $w = 10$.
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What is the perimeter of a rectangle with $l = 6$ and $w = 6$?
What is the perimeter of a rectangle with $l = 6$ and $w = 6$?
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$24$ units. For a square, $P = 4s = 4(6) = 24$ units.
$24$ units. For a square, $P = 4s = 4(6) = 24$ units.
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What is the area of a rectangle with $l = 11$ and $w = 1$?
What is the area of a rectangle with $l = 11$ and $w = 1$?
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$11$ square units. Multiply length times width: $11 \times 1 = 11$.
$11$ square units. Multiply length times width: $11 \times 1 = 11$.
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A rectangle has $A = 72$ and $w = 9$. What is $l$?
A rectangle has $A = 72$ and $w = 9$. What is $l$?
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$l = 8$. Divide area by width: $72 \div 9 = 8$.
$l = 8$. Divide area by width: $72 \div 9 = 8$.
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A rectangle has $P = 36$ and $w = 7$. What is $l$?
A rectangle has $P = 36$ and $w = 7$. What is $l$?
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$l = 11$. From $P = 2l + 2w$: $36 = 2l + 2(7)$, so $l = 11$.
$l = 11$. From $P = 2l + 2w$: $36 = 2l + 2(7)$, so $l = 11$.
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Which expression matches the perimeter of a rectangle: $l + w$ or $2(l + w)$?
Which expression matches the perimeter of a rectangle: $l + w$ or $2(l + w)$?
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$2(l + w)$. Perimeter adds all sides, which is $2(l + w)$.
$2(l + w)$. Perimeter adds all sides, which is $2(l + w)$.
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Find and correct the formula error: $A = 2l + 2w$ is labeled as area for a rectangle.
Find and correct the formula error: $A = 2l + 2w$ is labeled as area for a rectangle.
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Correct: $A = l \times w$. The given formula is for perimeter, not area.
Correct: $A = l \times w$. The given formula is for perimeter, not area.
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What is the area of a rectangle with $l = 8$ and $w = 5$?
What is the area of a rectangle with $l = 8$ and $w = 5$?
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$40$ square units. Multiply length times width: $8 \times 5 = 40$.
$40$ square units. Multiply length times width: $8 \times 5 = 40$.
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What is the perimeter of a rectangle with $l = 9$ and $w = 4$?
What is the perimeter of a rectangle with $l = 9$ and $w = 4$?
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$26$ units. Add all sides: $2(9) + 2(4) = 18 + 8 = 26$.
$26$ units. Add all sides: $2(9) + 2(4) = 18 + 8 = 26$.
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Find the missing width $w$ if $A = 48$ and $l = 6$ for a rectangle.
Find the missing width $w$ if $A = 48$ and $l = 6$ for a rectangle.
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$w = 8$. Divide area by length: $48 \div 6 = 8$.
$w = 8$. Divide area by length: $48 \div 6 = 8$.
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Find the missing length $l$ if $A = 63$ and $w = 7$ for a rectangle.
Find the missing length $l$ if $A = 63$ and $w = 7$ for a rectangle.
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$l = 9$. Divide area by width: $63 \div 7 = 9$.
$l = 9$. Divide area by width: $63 \div 7 = 9$.
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Find the missing width $w$ if $P = 30$ and $l = 10$ for a rectangle.
Find the missing width $w$ if $P = 30$ and $l = 10$ for a rectangle.
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$w = 5$. Use $P = 2l + 2w$: $30 = 2(10) + 2w$, so $w = 5$.
$w = 5$. Use $P = 2l + 2w$: $30 = 2(10) + 2w$, so $w = 5$.
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Find the missing length $l$ if $P = 44$ and $w = 8$ for a rectangle.
Find the missing length $l$ if $P = 44$ and $w = 8$ for a rectangle.
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$l = 14$. Use $P = 2l + 2w$: $44 = 2l + 2(8)$, so $l = 14$.
$l = 14$. Use $P = 2l + 2w$: $44 = 2l + 2(8)$, so $l = 14$.
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What is the missing length $l$ if a rectangle has $P = 18$ and $w = 4$?
What is the missing length $l$ if a rectangle has $P = 18$ and $w = 4$?
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$l = 5$. From $P = 2l + 2w$: $18 = 2l + 2(4)$, so $l = 5$.
$l = 5$. From $P = 2l + 2w$: $18 = 2l + 2(4)$, so $l = 5$.
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