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 square with 8 cm sides has a perimeter of 24 cm.
Corrected: A square with 8 cm sides has a perimeter of 32 cm.
The corrected sentence is: "A square with 8 cm sides has a perimeter of 32 cm." The error was wrong sum: the original sentence "A square with 8 cm sides has a perimeter of 24 cm." needed to be fixed.
2. Fix the sentence:
A rectangle 7 cm by 4 cm has an area of 22 square cm.
Corrected: A rectangle 7 cm by 4 cm has an area of 28 square cm.
The corrected sentence is: "A rectangle 7 cm by 4 cm has an area of 28 square cm." The error was wrong product: the original sentence "A rectangle 7 cm by 4 cm has an area of 22 square cm." needed to be fixed.
3. Fix the sentence:
Perimeter tells how much space is inside a shape.
Corrected: Perimeter tells the distance around a shape.
The corrected sentence is: "Perimeter tells the distance around a shape." The error was wrong definition: the original sentence "Perimeter tells how much space is inside a shape." needed to be fixed.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. A rectangle with sides 10 cm and 4 cm has a perimeter of 28 cm.
Add all four sides: 10 + 4 + 10 + 4 = 28 cm.
2. A square with sides of 9 m has an area of 81 square m.
Area of a square is side x side, so 9 x 9 = 81 square m.
3. Perimeter measures the distance around a shape.
Perimeter is the total distance you would walk if you went all the way around the outside of a shape.
4. A rectangle is 5 m long and 8 m wide. Its area is 40 square m.
Area = length x width, so 5 x 8 = 40 square m.
Part C: True or False?
Read each statement. Circle True or False.
1. A rectangle with sides 6 cm and 5 cm has a perimeter of 22 cm.
True False
True. Add all four sides: 6 + 5 + 6 + 5 = 22 cm.
2. A square with 7 cm sides has an area of 42 square cm.
True False
False. A square's area is side x side, so 7 x 7 = 49 square cm, not 42.
3. You add all four sides to find the perimeter of a rectangle.
True False
True. Perimeter means adding every side together, and a rectangle has four sides.