Surface area from a net: prisms and pyramids

Answer Key - Grade 7 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. Read this first

   Use this

   Grid, each square 0.5 in by 0.5 in. The net of the box: a row of four rectangles (3 by 1.5, 2 by 1.5, 3 by 1.5, 2 by 1.5) with a 3 by 2 rectangle joined above and another below.

2. 1.

   Ari's gift box is 3 in long, 2 in wide and 1.5 in tall. Its net has six rectangles. The ribbon is extra curly. What is its surface area in square inches?

   27

3. Use this

   The net of the box: a row of four rectangles (2.5 by 3, 2 by 3, 2.5 by 3, 2 by 3) with a 2.5 by 2 rectangle joined above and another below.

4. 2.

   Bo's storage box is 2.5 in long, 2 in wide and 3 in tall. Its net has six rectangles. It hides a lot of socks. What is its surface area in square inches?

   37

5. Use this

   The net: a row of three rectangles (6 by 6, 6 by 8, 6 by 10) with a triangle (sides 6, 8, 10) joined above and another below.

6. 3.

   Kira's toy ramp is a triangular prism 6 in long. Each end covers 24 square inches; its sides are 6, 8, 10 in. Zoom zoom. What is its surface area in square inches?

   192

7. Use this

   Grid, each square 0.5 cm by 0.5 cm. The net: a row of three rectangles (4 by 1.5, 4 by 2, 4 by 2.5) with a triangle (sides 1.5, 2, 2.5) joined above and another below.

8. 4.

   Luz's toy ramp is a triangular prism 4 cm long. Each end covers 1.5 square cm; its sides are 1.5, 2, 2.5 cm. Wheels ready. What is its surface area in square cm?

   27
9. 5.

   Milo's snack wedge is a triangular prism 3 in long. Each end covers 13.5 square inches; its sides are 4.5, 6, 7.5 in. It vanishes fast. What is its surface area in square inches?

   81

10. Use this

    Grid, each square 1 in by 1 in. The net: a row of four rectangles (3 by 6, 3 by 4, 3 by 3, 3 by 5) with a trapezoid (parallel sides 6 and 3, height 4, slanted side 5) joined above and another below.

11. 6.

    Noah's craft box is a prism 3 in long. Each end covers 18 square inches; its sides are 6, 3, 4, 5 in. Glitter everywhere. What is its surface area in square inches?

    90
12. 7.

    Grid, each square 1 in by 1 in. Pia's treasure box is a prism 2 in long. Each end covers 14 square inches; its sides are 5, 2, 4, 5 in. Shiny inside. What is its surface area in square inches?

    60
13. 8.

    Tala's model recycling bin is a prism 2 in long. Each end covers 22 square inches; its sides are 7, 4, 4, 5 in. It is tidy. What is its surface area in square inches?

    84
14. 9.

    Zee's castle tower roof has a base of 16 by 5 cm. Two faces cover 52 square cm each; two cover 25 square cm each. Flag up. What is its surface area in square cm?

    234
15. 10.

    Ari's castle tower roof has a base of 16 by 9 cm. Two faces cover 60 square cm each; two cover 45 square cm each. What is its surface area in square cm?

    354