Similar figures: corresponding sides, scale factor, and all circles are similar

Answer Key - Grade 10 Math Worksheet - Building Confidence

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

1. 1.

   Bo checks pairs of shapes by their side lengths, all in cm. Which pair is similar?

   • Rectangles 4 by 6 and 10 by 15
   • Rectangles 2 by 3 and 4 by 7
   • Rectangles 3 by 5 and 6 by 8, with 90° angles
   • Rectangles 5 by 7 and 8 by 10
2. 2.

   Esme checks pairs of shapes by their side lengths, all in cm. Which pair is similar?

   • Triangles with sides 12, 5, 13 and 10, 26, 24
   • Triangles with sides 6, 9, 12 and 8, 12, 15
   • Triangles with sides 5, 7, 9 and 8, 10, 12
   • Isosceles triangles with sides 5, 5, 6 and 5, 5, 8
3. 3.

   Jun checks pairs of shapes by their side lengths, all in cm. Which pair is similar?

   • Rectangles 6 by 9 and 9 by 12
   • Rectangles 8 by 10 and 12 by 16
   • Rectangles 9 by 12 and 6 by 8
   • A 5 by 5 square and a 5 by 10 rectangle
4. 4.

   Kira scales a boat drawing. △CDF ~ △UQS, with CD = 6, DF = 8, CF = 10 (cm). QS = 20 cm. What is the scale factor from △CDF to △UQS?

   5/2
5. 5.

   Luz scales a ramp drawing. △CDF ~ △SUQ, with CD = 4, DF = 6, CF = 8 (cm). SQ = 14 cm. What is the scale factor from △CDF to △SUQ?

   7/4
6. 6.

   Milo scales a star drawing. △UQS ~ △CDF, with UQ = 15, QS = 20, US = 25 (cm). DF = 8 cm. What is the scale factor from △UQS to △CDF?

   2/5
7. 7.

   Noah scales a park drawing. △CDF ~ △QSU, with CD = 9, DF = 12, CF = 15 (cm). SU = 20 cm. What is the scale factor from △CDF to △QSU?

   5/3
8. 8.

   Ren scales a cheese plan. △CDF ~ △UQS, with CD = 4 and DF = 6 in the first triangle. UQ = 12. How long is QS?

   18
9. 9.

   Tala scales a pizza plan. △CDF ~ △UQS, with CD = 8 and DF = 12 in the first triangle. UQ = 6. How long is QS?

   9
10. 10.

    Zee scales a map plan. △CDF ~ △UQS, with CD = 6 and DF = 12 in the first triangle. UQ = 4. How long is QS?

    8