Triangle similarity: AA, SSS and SAS

Answer Key - Grade 10 Math Worksheet - Building Confidence

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

1. 1.

   Jun compares two tent doors, △CDF and △QSU. Which rule proves △CDF ~ △QSU?

   • AA
   • SSS~
   • Not enough to tell
   • SAS~
2. 2.

   Luz compares two sails, △CDF and △QSU. Which rule proves △CDF ~ △QSU?

   • SSS~
   • Not enough to tell
   • SAS~
   • AA
3. 3.

   Milo compares two roof fronts, △CDF and △QSU. Which rule proves △CDF ~ △QSU?

   • SAS~
   • AA
   • SSS~
   • Not enough to tell

4. Read this first

   Ratio table

   Columns small triangle | large triangle; rows shortest 4 | 8, middle 6 | 12, longest 7 | ?. Lengths in cm.

5. 4.

   Noah checks two triangle tiles and wants them similar by SSS~. The table pairs the sides by size. How long must the longest side of the large triangle be, in cm?

   14

6. Ratio table

   Columns small triangle | large triangle; rows shortest 6 | 10, middle 9 | 15, longest 10 | ?. Lengths in cm.

7. 5.

   Pia cuts two paper triangles for a mobile and wants them similar by SSS~. The table pairs the sides by size. How long must the longest side of the large triangle be, in cm?

   50/3

8. Ratio table

   Columns small triangle | large triangle; rows shortest 3 | 9, middle 5 | 15, longest 6 | ?. Lengths in cm.

9. 6.

   Ren plans a small and a big triangle kite and wants them similar by SSS~. The table pairs the sides by size. How long must the longest side of the large triangle be, in cm?

   18

10. Ratio table

    Columns small triangle | large triangle; rows shortest 8 | 10, middle 12 | 15, longest 14 | ?. Lengths in cm.

11. 7.

    Tala measures two triangle window panes and wants them similar by SSS~. The table pairs the sides by size. How long must the longest side of the large triangle be, in cm?

    35/2
12. 8.

    Zee studies a folding chair from the side. CG and DF cross at Y, CD ∥ GF, and △YCD ~ △YGF by AA. How long is YG, in cm?

    15
13. 9.

    Ari opens a pair of scissors. CG and DF cross at Y, CD ∥ GF, and △YCD ~ △YGF by AA. How long is YG, in cm?

    15
14. 10.

    Bo looks at a folding table from the side. CG and DF cross at Y, CD ∥ GF, and △YCD ~ △YGF by AA. How long is YG, in cm?

    12