Worksheets — Set 18

Geometry · Similarity and right-triangle trigonometry

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

Warm-up

1. Similar triangles: sides 22, 23, and 24. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 21, find BC/EF = ___ 3. Right triangle: opposite=22, hypotenuse=24. sin θ = ___

_See printable PDF for diagram._

Written practice

1. Similar triangles: sides 21, 22, and 23. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 20, find BC/EF = ___ 3. Right triangle: opposite=21, hypotenuse=23. sin θ = ___ 4. Find missing side using tan 45° = ___ 5. Dilation scale factor 3.3. Image length? ___ 6. Explain why the triangles are similar. 7. Similar triangles: sides 24, 25, and 26. Scale factor? ___ 8. If ΔABC ~ ΔDEF and AB/DE = 23, find BC/EF = ___

___________________________ ___________________________ ___________________________ ___________________________

More written practice

1. Right triangle: opposite=24, hypotenuse=26. sin θ = ___ 2. Dilation scale factor 3.6. Image length? ___ 3. Similar triangles: sides 27, 28, and 29. Scale factor? ___ 4. If ΔABC ~ ΔDEF and AB/DE = 26, find BC/EF = ___ 5. Right triangle: opposite=27, hypotenuse=29. sin θ = ___ 6. Dilation scale factor 3.9000000000000004. Image length? ___

___________________________ ___________________________ ___________________________ ___________________________ ___________________________

Patterns and rules

1. Similar triangles: sides 38, 39, and 40. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 37, find BC/EF = ___ 3. Right triangle: opposite=38, hypotenuse=40. sin θ = ___

_See printable PDF for diagram._

___________________________ ___________________________ ___________________________ ___________________________

Stretch

1. Similar triangles: sides 46, 47, and 48. Scale factor? ___ 2. If ΔABC ~ ΔDEF and AB/DE = 45, find BC/EF = ___

___________________________ ___________________________ ___________________________ ___________________________

Parent tip: Set up proportions from similar triangles