Worksheets — Set 15

Trigonometry · Right-triangle trigonometry

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

Warm-up

1. Similar triangles: sides 19, 20, and 21. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 18, find BC/EF = ___ 3. Right triangle: opposite=19, hypotenuse=21. sin θ = ___

_See printable PDF for diagram._

Written practice

1. Similar triangles: sides 18, 19, and 20. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 17, find BC/EF = ___ 3. Right triangle: opposite=18, hypotenuse=20. sin θ = ___ 4. Find missing side using tan 45° = ___ 5. Dilation scale factor 3. Image length? ___ 6. Explain why the triangles are similar. 7. Similar triangles: sides 21, 22, and 23. Scale factor? ___ 8. If ΔABC ~ ΔDEF and AB/DE = 20, find BC/EF = ___

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More written practice

1. Right triangle: opposite=21, hypotenuse=23. sin θ = ___ 2. Dilation scale factor 3.3. Image length? ___ 3. Similar triangles: sides 24, 25, and 26. Scale factor? ___ 4. If ΔABC ~ ΔDEF and AB/DE = 23, find BC/EF = ___ 5. Right triangle: opposite=24, hypotenuse=26. sin θ = ___ 6. Dilation scale factor 3.6. Image length? ___

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Patterns and rules

1. Similar triangles: sides 35, 36, and 37. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 34, find BC/EF = ___ 3. Right triangle: opposite=35, hypotenuse=37. sin θ = ___

_See printable PDF for diagram._

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Parent tip: Set up proportions from similar triangles