How scaling changes area

Answer Key - Grade 7 Math Worksheet

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

1. 1.

   Kira draws the school hall on a plan at the scale 2 cm : 5 m. The hall is 4 cm by 6 cm on the plan. How many square meters is the real hall?

   150
2. 2.

   Milo plans a camping tent pad at the scale 5 cm : 2 m. The pad is 10 cm by 20 cm on the plan. How many square meters is the real pad?

   32
3. 3.

   Ren's garden covers 45 square meters. The plan has the scale 2 cm : 3 m. How many square cm does the garden cover on the plan?

   20
4. 4.

   Tala's tiny house covers 20 square meters. The plan has the scale 5 cm : 2 m. How many square cm does the house cover on the plan?

   125
5. 5.

   Side 1 | 1.5, area 1 | ? (the picture is not printed to size). Zee builds model window B as a copy of window A, with every side 1.5 times as long. B covers how many times as much area as A?

   2.25
6. 6.

   Side 1 | 2.5, area 1 | ? (the picture is not printed to size). Ari's tabletop B is a copy of tabletop A, with every side 2.5 times as long. B covers how many times as much area as A?

   6.25
7. 7.

   Side 1 | 0.4, area 1 | ? (the picture is not printed to size). Bo shrinks poster A onto a flyer B, with every side 0.4 times as long. B covers how many times as much area as A?

   0.16
8. 8.

   Side 1 | ?, area 1 | 9 (the picture is not printed to size). Esme cuts a small sail A and a bigger sail B, similar triangles. B covers 9 times as much area as A. What is the scale factor from A to B?

   3
9. 9.

   Side 1 | ?, area 1 | 16 (the picture is not printed to size). Jun builds a small kite A and a bigger kite B, similar shapes. B covers 16 times as much area as A. What is the scale factor from A to B?

   4
10. 10.

    Side 1 | ?, area 1 | 25 (the picture is not printed to size). Kira prints a small flyer A and a bigger poster B, similar rectangles. B covers 25 times as much area as A. What is the scale factor from A to B?

    5