Perimeter and Area — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
A rectangle with sides 5 cm and 3 cm has a perimeter of 15 cm.
Corrected: A rectangle with sides 5 cm and 3 cm has a perimeter of 16 cm.
The corrected sentence is: "A rectangle with sides 5 cm and 3 cm has a perimeter of 16 cm.". The original sentence "A rectangle with sides 5 cm and 3 cm has a perimeter of 15 cm." contained an error that needed to be fixed.
2. Fix the sentence:
A rectangle that is 4 units long and 2 units wide has an area of 6 square units.
Corrected: A rectangle that is 4 units long and 2 units wide has an area of 8 square units.
The corrected sentence is: "A rectangle that is 4 units long and 2 units wide has an area of 8 square units.". The original sentence "A rectangle that is 4 units long and 2 units wide has an area of 6 square units." contained an error that needed to be fixed.
3. Fix the sentence:
The perimeter of a shape is measured in square centimeters.
Corrected: The perimeter of a shape is measured in centimeters.
The corrected sentence is: "The perimeter of a shape is measured in centimeters.". The original sentence "The perimeter of a shape is measured in square centimeters." contained an error that needed to be fixed.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. A rectangle has sides of 6 cm and 4 cm. Its perimeter is 20 cm.
Perimeter = 6 + 4 + 6 + 4 = 20 cm.
2. A rectangle is 3 units long and 5 units wide. Its area is 15 square units.
Area = 3 × 5 = 15 square cm.
3. To find the perimeter of a shape, you add all the side lengths.
Perimeter is found by adding all the side lengths together.
4. A square with sides of 7 cm has a perimeter of 28 cm.
Perimeter = 4 × 7 = 28 cm.
Part C: True or False?
Read each statement. Circle True or False.
1. A rectangle that is 6 units long and 3 units wide has an area of 18 square units.
True False
True — perimeter measures the total distance around the outside of a shape.
2. Perimeter is measured in square units.
True False
False — area is measured in square units, such as square centimeters.
3. A rectangle with sides 2 cm and 5 cm has a perimeter of 14 cm.
True False
True — perimeter = 4 × 5 = 20 cm.