Worksheets — Set 1

Trigonometry · Honors · Law of sines and law of cosines

Print and write your answers. Use diagrams to show thinking.

Warm-up

1. Similar triangles: sides 5, 6, and 7. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 4, find BC/EF = ___ 3. Right triangle: opposite=5, hypotenuse=7. sin θ = ___

_See printable PDF for diagram._

Written practice

1. Similar triangles: sides 4, 5, and 6. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 3, find BC/EF = ___ 3. Right triangle: opposite=4, hypotenuse=6. sin θ = ___ 4. Find missing side using tan 45° = ___ 5. Dilation scale factor 1.6. Image length? ___ 6. Explain why the triangles are similar. 7. Similar triangles: sides 7, 8, and 9. Scale factor? ___ 8. If ΔABC ~ ΔDEF and AB/DE = 6, find BC/EF = ___

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More written practice

1. Right triangle: opposite=7, hypotenuse=9. sin θ = ___ 2. Dilation scale factor 1.9. Image length? ___ 3. Similar triangles: sides 10, 11, and 12. Scale factor? ___ 4. If ΔABC ~ ΔDEF and AB/DE = 9, find BC/EF = ___ 5. Right triangle: opposite=10, hypotenuse=12. sin θ = ___ 6. Dilation scale factor 2.2. Image length? ___

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Patterns and rules

1. Similar triangles: sides 21, 22, and 23. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 20, find BC/EF = ___ 3. Right triangle: opposite=21, hypotenuse=23. sin θ = ___

_See printable PDF for diagram._

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Parent tip: Set up proportions from similar triangles