Worksheets — Set 11

Geometry · Similarity and right-triangle trigonometry

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

Warm-up

1. Similar triangles: sides 15, 16, and 17. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 14, find BC/EF = ___ 3. Right triangle: opposite=15, hypotenuse=17. sin θ = ___

_See printable PDF for diagram._

Written practice

1. Similar triangles: sides 14, 15, and 16. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 13, find BC/EF = ___ 3. Right triangle: opposite=14, hypotenuse=16. sin θ = ___ 4. Find missing side using tan 45° = ___ 5. Dilation scale factor 2.6. Image length? ___ 6. Explain why the triangles are similar. 7. Similar triangles: sides 17, 18, and 19. Scale factor? ___ 8. If ΔABC ~ ΔDEF and AB/DE = 16, find BC/EF = ___

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More written practice

1. Right triangle: opposite=17, hypotenuse=19. sin θ = ___ 2. Dilation scale factor 2.9000000000000004. Image length? ___ 3. Similar triangles: sides 20, 21, and 22. Scale factor? ___ 4. If ΔABC ~ ΔDEF and AB/DE = 19, find BC/EF = ___ 5. Right triangle: opposite=20, hypotenuse=22. sin θ = ___ 6. Dilation scale factor 3.2. Image length? ___

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Patterns and rules

1. Similar triangles: sides 31, 32, and 33. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 30, find BC/EF = ___ 3. Right triangle: opposite=31, hypotenuse=33. sin θ = ___

_See printable PDF for diagram._

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Parent tip: Set up proportions from similar triangles