Worksheets — Set 4

Geometry · Similarity and right-triangle trigonometry

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

Warm-up

1. Similar triangles: sides 8, 9, and 10. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 7, find BC/EF = ___ 3. Right triangle: opposite=8, hypotenuse=10. sin θ = ___

_See printable PDF for diagram._

Written practice

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 = ___ 4. Find missing side using tan 45° = ___ 5. Dilation scale factor 1.9. Image length? ___ 6. Explain why the triangles are similar. 7. Similar triangles: sides 10, 11, and 12. Scale factor? ___ 8. If ΔABC ~ ΔDEF and AB/DE = 9, find BC/EF = ___

___________________________ ___________________________ ___________________________ ___________________________

More written practice

1. Right triangle: opposite=10, hypotenuse=12. sin θ = ___ 2. Dilation scale factor 2.2. Image length? ___ 3. Similar triangles: sides 13, 14, and 15. Scale factor? ___ 4. If ΔABC ~ ΔDEF and AB/DE = 12, find BC/EF = ___ 5. Right triangle: opposite=13, hypotenuse=15. sin θ = ___ 6. Dilation scale factor 2.5. Image length? ___

___________________________ ___________________________ ___________________________ ___________________________ ___________________________

Patterns and rules

1. Similar triangles: sides 24, 25, and 26. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 23, find BC/EF = ___ 3. Right triangle: opposite=24, hypotenuse=26. sin θ = ___

_See printable PDF for diagram._

___________________________ ___________________________ ___________________________ ___________________________

Parent tip: Set up proportions from similar triangles