Worksheets — Set 6

Geometry · Similarity and right-triangle trigonometry

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

Warm-up

1. Similar triangles: sides 10, 11, and 12. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 9, find BC/EF = ___ 3. Right triangle: opposite=10, hypotenuse=12. sin θ = ___

_See printable PDF for diagram._

Written practice

1. Similar triangles: sides 9, 10, and 11. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 8, find BC/EF = ___ 3. Right triangle: opposite=9, hypotenuse=11. sin θ = ___ 4. Find missing side using tan 45° = ___ 5. Dilation scale factor 2.1. Image length? ___ 6. Explain why the triangles are similar. 7. Similar triangles: sides 12, 13, and 14. Scale factor? ___ 8. If ΔABC ~ ΔDEF and AB/DE = 11, find BC/EF = ___

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More written practice

1. Right triangle: opposite=12, hypotenuse=14. sin θ = ___ 2. Dilation scale factor 2.4. Image length? ___ 3. Similar triangles: sides 15, 16, and 17. Scale factor? ___ 4. If ΔABC ~ ΔDEF and AB/DE = 14, find BC/EF = ___ 5. Right triangle: opposite=15, hypotenuse=17. sin θ = ___ 6. Dilation scale factor 2.7. Image length? ___

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Patterns and rules

1. Similar triangles: sides 26, 27, and 28. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 25, find BC/EF = ___ 3. Right triangle: opposite=26, hypotenuse=28. sin θ = ___

_See printable PDF for diagram._

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Parent tip: Set up proportions from similar triangles