Plainfield Board of Education
Office of Elementary Mathematics
Name: _____________________________________
Date: ________________
Teacher: ___________________________________
Grade 3
Unit 5 Assessment - Understanding Area and Perimeter Answer Key
Section 1: Each question is worth 1 point.
1.
Jacob wants to tile the bathroom floor using 1 foot tiles. How many square foot tiles will
he need?
(3.MD.7)
6 feet
4 feet
24 tiles
2. What is the area of the rectangle above that is not shaded?
Each square is 1 unit
A. 18 square units
B. 10 square units
C. 8 square units
D. 9 square units
(3.MD.6)
Plainfield Board of Education
Office of Elementary Mathematics
3. A drawing of the Johnson's deck is shown below.
(3.MD.7)
Figure not drawn to scale.
What is the area of their deck?
A. 120 square feet
B. 66 square feet
C. 190 square feet
D. 48 square feet
4. Natalia just measured the living room in her dollhouse.
What is the area of the living room?
A. 80 sq cm
B. 72 sq cm
C. 84 sq cm
D. 40 sq cm
(3.MD.5)
Plainfield Board of Education
Office of Elementary Mathematics
5. Which of the following expressions could be used to find the area of the rectangle below?
(3.MD.7)
A. 3 × 4 + 3 × 5
B. 3 × 4 + 5
C. 3 × 4 × 5
D. 4 + 5 × 3
6. Which of the following expressions could be used to find the area of the rectangle below?
(3.MD.7)
A. 8 × 1 × 3
B. 1 + 3 × 8
C. 8 × 1 + 8 × 3
D. 8 × 1 + 3
7. The surface area of Jah’quan’s laptop is 24 square cm. What could be the length and width of
his laptop?
(3.MD.7)
(possible solution)
Length of laptop: ______6_______cm.
Width of laptop: ____4______cm
Plainfield Board of Education
Office of Elementary Mathematics
Use the diagram below for problems 8, 9, and 10.
8. What is the area of object X?
(3.MD.6)
A. 3 square centimeters
B. 4 square centimeters
C. 11 square centimeters
D. 4 square centimeters
9. Which object has the largest area?
_______object U____________
10. What is the difference in the perimeter between objects U and object Z?
12 cm - 10 cm = 2 cm
(3.MD.5)
(3.MD.8)
Plainfield Board of Education
Office of Elementary Mathematics
11. Which of the following is true?
(3.MD.7, 3.MD.8)
A. The rectangles have the same perimeter, but different areas.
B. The rectangles have different areas and perimeters.
C. The rectangles have the same area, but different perimeters.
D. The rectangles have the same area and perimeter.
12. Draw a shape with an area of 15 square units.
(3.MD.5)
Each square is 1 unit
13. Molly is planting a garden which will be shaped like a square. If the length of one side of her
garden is 4 meters, what is the area of her garden?
(3.MD.7)
A. 8 square meters
B. 15 square meters
C. 13 square meters
D. 16 square meters
Plainfield Board of Education
Office of Elementary Mathematics
14. The perimeter of the following triangle is 6 inches. Two sides of the triangle are given. What
is the length of the missing side?
(3.MD.8)
A. 4 inches
B. 2 inches
C. 7 inches
D. 5 inches
15. Robbie's kite has two sides that measure 18 cm each and two sides that measure 13 cm each.
What is the perimeter of Robbie's kite?
(3.MD.8)
A. 21 cm
B. 31 cm
C. 62 cm
D. 49 cm
16. What is the perimeter of the polygon pictured below?
A. 14 feet
B. 17 feet
C. 15 feet
D. 5 feet
(3.MD.8)
Plainfield Board of Education
Office of Elementary Mathematics
17. Maggie's house is shaped like a rectangle. The length of her house is 26 meters and the width
is 37 meters. What is the perimeter of Maggie's house?
(3.MD.8)
A. 63 meters
B. 148 meters
C. 104 meters
D. 126 meters
18. Use the grid below to draw a polygon with a perimeter of 12 units.
(3.MD.8)
(possible solution)
Each square is 1 unit.
19. Michael has a room in his house that is shaped like a square. The perimeter of the room is 20
feet. What is the length of one side of the room?
(3.MD.8)
A. 6 feet
B. 5 feet
C. 4 feet
D. 10 feet
20. Molly is planting a garden which will be shaped like a square. If the length of one side of her
garden is 6 meters, what is the perimeter of her garden?
(3.MD.8)
A. 18 meters
B. 36 meters
C. 12 meters
D. 24 meters
Plainfield Board of Education
Office of Elementary Mathematics
21. The border of a puzzle is shaped like a trapezoid. The lengths of the sides are 20 inches, 9
inches, 11 inches, and 13 inches. What is the perimeter of the puzzle?
(3.MD.8)
A. 47 inches
B. 38 inches
C. 53 inches
D. 33 inches
22. The perimeter of the following polygon is 36 cm. What is the length of the missing side?
(3.MD.8)
?
5 cm
A. 7 cm
B. 8 cm
C. 2 cm
D. 5 cm
Plainfield Board of Education
Office of Elementary Mathematics
Section 2: Open Ended Response (worth 3 points).
23. Draw a rectangle that has a perimeter of 14 units and an area of 12 square units.
(3.MD.5, 3.MD.8)
Each square is 1 unit.
The sides of the rectangle measure:
_______3_______ units and _______4______ units.
Write a number sentence to show:

The Area

The Perimeter: ___3 + 4 + 3 + 4 = 14 units______
___3 x 4 = 12 square units______