Perimeter, Area, and Surface Area — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A box measures 2.5 ft by 3 ft by 4 ft. What is its volume?
A) 30 cubic feet
B) 24 cubic feet
C) 9.5 cubic feet
D) 27 cubic feet
2.5 times 3 equals 7.5; 7.5 times 4 equals 30 cubic feet exactly.
2. Prism A is 4 by 5 by 6 and Prism B is 3 by 4 by 10. Which has greater volume?
A) Prism A only
B) Prism B (120 cubic units vs 120)
C) Both equal at 120 cubic units
D) Cannot be determined
4 times 5 times 6 is 120 and 3 times 4 times 10 is 120, so equal.
3. A cube has side length one half ft. What is its volume?
A) 1 cubic foot
B) 0.125 cubic feet
C) 0.25 cubic feet
D) 1.5 cubic feet
Half cubed is one eighth, which equals 0.125 cubic feet exactly.
4. Box A holds 24 cubic in; box B has dimensions 2 by 3 by 5 in. How much more does box B hold?
A) 6 cubic inches less than A
B) Same as A, 24 cubic in
C) 30 cubic inches more total
D) 6 cubic inches more than A
Box B is 2 times 3 times 5 equals 30; 30 minus 24 equals 6 more.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A prism with base area 12 sq ft and height 0.5 ft has volume 6 cubic feet.
12 times 0.5 equals 6 cubic feet of prism volume.
2. A cube with side 3 ft has surface area 54 square feet (6 times s squared).
Six faces times 3 squared is 6 times 9, which equals 54.
3. A box 2 by 4 by 5 in needs paint on all faces; surface area is 76 square inches.
2 times (8 plus 10 plus 20) equals 2 times 38, which is 76.
4. A 1 by 1 by 1 ft cube fits inside a 2 by 2 by 2 ft cube; the empty space is 7 cubic feet.
Two cubed is 8 and one cubed is 1; 8 minus 1 equals 7.
5. If only 3 of 6 faces of a 4 by 4 by 4 ft cube are painted, painted area is 48 square feet.
Three faces of 16 square feet each give 48 square feet painted.