Perimeter and Area — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. A rectangle with sides 7 cm and 3 cm has a perimeter of 20 cm.
Perimeter adds 7 + 3 + 7 + 3 = 20 cm because opposite sides match. You can also double 7 + 3 = 10 to get 20.
2. A rectangle that is 6 m long and 4 m wide has an area of 24 square m.
Multiplying 6 × 4 = 24 square m gives the area. Picture 6 rows of 4 unit squares filling the rectangle.
3. A square with 9 cm sides has a perimeter of 36 cm.
A square has four equal sides, so 4 × 9 = 36 cm. Adding 9 + 9 + 9 + 9 also gives 36.
4. A garden is 8 feet long and 5 feet wide. Its area is 40 square feet.
The garden's area is 8 × 5 = 40 square feet. That is how many 1-foot squares would cover the ground.
5. A rectangle with sides 10 m and 2 m has a perimeter of 24 m.
Adding all four sides gives 10 + 2 + 10 + 2 = 24 m. Two long sides total 20 and two short sides total 4, making 24.
6. A square tile is 3 inches on each side. Its area is 9 square inches.
Each side of the tile is 3 inches, so 3 × 3 = 9 square inches of area. The tile holds nine 1-inch squares inside.
7. A rug is 5 feet by 8 feet. Its perimeter is 26 feet.
Perimeter is 5 + 8 + 5 + 8 = 26 feet around the rug. Doubling 5 + 8 = 13 gives the same 26.
8. A square window is 7 cm on each side. Its area is 49 square cm.
All four sides of the window measure 7 cm, so 7 × 7 = 49 square cm fills the inside. That is 49 little squares of glass.
9. A square garden has sides of 6 m. Its perimeter is 24 m.
A square's perimeter is 4 times one side: 4 × 6 = 24 m. Adding 6 + 6 + 6 + 6 also gives 24.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Rectangle 4 cm × 3 cm area
→ 12 square cm
16 cm
Square 5 cm perimeter
→ 20 cm
64 square cm
Rectangle 6 cm × 2 cm perimeter
→ 16 cm
12 square cm
Square 8 cm area
→ 64 square cm
20 cm
Area uses multiplication and perimeter uses addition around the shape: 4 × 3 = 12 square cm; the square with 5 cm sides has perimeter 4 × 5 = 20 cm; the 6 cm by 2 cm rectangle has perimeter 6+2+6+2 = 16 cm; the 8 cm square has area 8 × 8 = 64 square cm.