Similar shapes: matching sides and angles

Answer Key - Grade 7 Math Worksheet

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

1. Read this first

   Use the table

   A, cm	B, cm
   20	50 for the matching sides
   ?	75 for the other sides

2. 1.

   Pia's small kite (A) and big kite (B) are similar. A's width is 20 cm and B's matching width is 50 cm. B is 75 cm tall. How many cm tall is A?

   30
3. 2.

   Ren cuts a small paper pennant (A) and a bigger one (B), similar triangles. A's base is 4 cm and B's is 6 cm. B is 18 cm long. How many cm long is A?

   12
4. 3.

   Tala paints a small model window (A) and a bigger one (B), similar rectangles. A's width is 12 cm and B's is 30 cm. B is 35 cm tall. How many cm tall is A?

   14
5. 4.

   One row 6 | 15 for the matching sides, with a box for the multiplier from A to B. Zee compares a flyer (A) and a poster (B), similar rectangles. The flyer is 6 cm wide and the poster is 15 cm wide. What is the scale factor from A to B?

   2.5
6. 5.

   One row 10 | 16 for the matching sides, with a box for the multiplier from A to B. Bo builds a castle model (A) and a bigger model (B), similar shapes. A's tower is 10 cm tall and B's is 16 cm tall. What is the scale factor from A to B?

   1.6

7. Sketch, not to scale

   Rectangle A has a long side of 9 cm and a short side of 6 cm; rectangle B is similar, with only its short side marked 15 cm.

8. 6.

   Esme paints two similar windows, A and B. A's long side is 9 cm and its short side is 6 cm. B's short side is 15 cm. How many cm long is B's long side?

   22.5
9. 7.

   Jun sews two similar doll quilts, A and B. A's long side is 12 inches; its short side is 8 inches. B's long side is 36 inches. How many inches long is B's short side?

   24
10. 8.

    Kira has two similar TV screens, A and B. A's long side is 10 inches; its short side is 6 inches. B's short side is 15 inches. How many inches long is B's long side?

    25
11. 9.

    Ren labels two similar warning signs. Triangle ABC is similar to triangle FDE. Which side of triangle FDE matches side AB?

    • side DE
    • side EF
    • side DF
12. 10.

    Tala labels two similar sails. Triangle ABC is similar to triangle EFD. Which side of triangle EFD matches side BC?

    • side EF
    • side DF
    • side DE