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. 2.

   Esme's wooden block is 3.5 cm long, 1 cm wide and 2 cm tall. Its net has six rectangles. It has survived many towers. What is its surface area in square cm?

   25

4. Use this

   Grid, each square 1 cm by 1 cm. The net: a row of three rectangles (7 by 3, 7 by 4, 7 by 5) with a triangle (sides 3, 4, 5) joined above and another below.

5. 3.

   Jun's cheese wedge is a triangular prism 7 cm long. Each end covers 6 square cm; its sides are 3, 4, 5 cm. Cheese please. What is its surface area in square cm?

   96
6. 4.

   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

7. 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.

8. 5.

   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
9. 6.

   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
10. 7.

    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
11. 8.

    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
12. 9.

    Bo's playhouse roof has a base of 9 by 5 cm. Two faces cover 29.25 square cm each; two cover 18.75 square cm each. What is its surface area in square cm?

    141
13. 10.

    Esme's pyramid tent has a base of 18 by 10 cm. Two faces cover 117 square cm each; two cover 75 square cm each. Snacks await. What is its surface area in square cm?

    564