Study Guide — HSG.CO.A.2
Represent transformations in the plane using, e
Use transformations and rigid motions to prove figures are congruent.
What this standard means
- Represent transformations in the plane using, e.g., transparencies and geometry software; describe transformations as functions that take points in the plane as inputs and give other points as outputs. Compare transformations that preserve distance and angle to those that do not (e.g., translation versus horizontal stretch).
- Apply represent transformations in the plane using, e with models and explanation
- Describes transformations precisely
_See printable PDF for diagram._
How to use the 20 practice sets
| Sets | When to use | | --- | --- | | 1–5 | Intro — explore together, short written items | | 6–10 | Core skills — diagrams and written practice | | 11–15 | Mixed review — explain thinking | | 16–20 | Stretch — word problems and mastery tasks |
Pacing: 10–15 minutes per session.
How to practice
1. Name the transformation sequence 2. Mark corresponding parts on diagrams 3. State which congruence criterion applies
_See printable PDF for diagram._
Common mistakes
- Assuming congruence without justification
- Wrong correspondence of vertices
Review and practice tests
1. Start Review 1/10 when sets 1–3 feel comfortable. 2. Move up one review level with little help. 3. Use Practice Test 4/10–6/10 for mid-standard checks. 4. Practice Test 10/10 is the mastery bar for HSG.CO.A.2.
- [ ] Describes transformations precisely
- [ ] Uses congruence criteria correctly
- [ ] Completes logical proof steps
Materials for this standard
- Practice Problems — 20 printable sets
- Review — 10 difficulty levels
- Practice Test — 10 difficulty levels
- Answer key — for parents and tutors