Perimeter and Area — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A rectangle is 12 cm long and 5 cm wide. What is its perimeter?
A) 17 cm
B) 34 cm
C) 60 cm
D) 24 cm
Perimeter = 12 + 5 + 12 + 5 = 34 cm. You add all four sides of the rectangle.
2. A square has an area of 36 square cm. How long is each side?
A) 9 cm
B) 4 cm
C) 6 cm
D) 8 cm
Since 6 x 6 = 36, each side must be 6 cm. You need to find which number times itself equals 36.
3. Which rectangle has an area of 30 square m?
A) 3 m × 9 m
B) 5 m × 6 m
C) 4 m × 8 m
D) 7 m × 4 m
5 x 6 = 30 square m, which matches the target area. The other choices multiply to different numbers.
4. A room is 8 m by 6 m. If carpet costs $1 per square m, what is the total cost?
A) $28
B) $14
C) $48
D) $56
First find the area: 8 x 6 = 48 square m. At $1 per square m, the total cost is 48 x $1 = $48.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A rectangle is 14 m long and 3 m wide. Its perimeter is 34 m.
Add all four sides: 14 + 3 + 14 + 3 = 34 m.
2. A square patio has 11 ft sides. Its area is 121 square ft.
A square's area is side x side, so 11 x 11 = 121 square ft.
3. A flag is 9 inches long and 6 inches wide. Its area is 54 square inches.
Area = length x width, so 9 x 6 = 54 square inches.
4. A rectangle has sides 7 cm and 5 cm. Its perimeter is 24 cm.
Add all four sides: 7 + 5 + 7 + 5 = 24 cm.
5. A classroom floor is 10 m long and 8 m wide. Its area is 80 square m.
Area = length x width, so 10 x 8 = 80 square m.