Worksheets — Set 3

Trigonometry · Right-triangle trigonometry

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

Warm-up

1. Similar triangles: sides 7, 8, and 9. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 6, find BC/EF = ___ 3. Right triangle: opposite=7, hypotenuse=9. sin θ = ___

_See printable PDF for diagram._

Written practice

1. Similar triangles: sides 6, 7, and 8. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 5, find BC/EF = ___ 3. Right triangle: opposite=6, hypotenuse=8. sin θ = ___ 4. Find missing side using tan 45° = ___ 5. Dilation scale factor 1.8. Image length? ___ 6. Explain why the triangles are similar. 7. Similar triangles: sides 9, 10, and 11. Scale factor? ___ 8. If ΔABC ~ ΔDEF and AB/DE = 8, find BC/EF = ___

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More written practice

1. Right triangle: opposite=9, hypotenuse=11. sin θ = ___ 2. Dilation scale factor 2.1. Image length? ___ 3. Similar triangles: sides 12, 13, and 14. Scale factor? ___ 4. If ΔABC ~ ΔDEF and AB/DE = 11, find BC/EF = ___ 5. Right triangle: opposite=12, hypotenuse=14. sin θ = ___ 6. Dilation scale factor 2.4. Image length? ___

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Patterns and rules

1. Similar triangles: sides 23, 24, and 25. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 22, find BC/EF = ___ 3. Right triangle: opposite=23, hypotenuse=25. sin θ = ___

_See printable PDF for diagram._

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Parent tip: Set up proportions from similar triangles