#### MAT-HS.G-CO.09.a

 MAT-HS Targeted Standards(G) Concept: Geometry(CO) Domain: CongruenceCluster: Prove geometric theorems MAT-HS.G-CO.09.a Prove theorems about lines and angles. Theorems include but are not limited to: vertical angles are congruent; when a transversal crosses parallel lines, alternate interior angles are congruent and corresponding angles are congruent; points on a perpendicular bisector of a line segment are exactly those equidistant from the segment’s endpoints.

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## Proficiency Scale

 Score Description Sample Activity Advanced In addition to Score 3.0, the student demonstrates in-depth inferences and applications regarding more complex material that go beyond end of instruction expectations. Error analysis (find errors in a given proof, fix the error and explain why it was incorrect) Concepts: Vertical Angles Angles created by parallel lines and a transversal Perpendicular Bisector theorems - 3.5 In addition to Score 3.0 performance, the student demonstrates in-depth inferences and applications regarding the more complex content with partial success. Proficient “The Standard.” The student demonstrates no major errors or omissions regarding any of the information and processes that were end of instruction expectations. Identify relevant given information Arrange reasoning in a logical sequence Support reasoning using appropriate justifications (theorems, postulates, definitions, etc.) Concepts: Vertical Angles Angles created by parallel lines and a transversal Perpendicular Bisector theorems 2.5 The student demonstrates no major errors or omissions regarding the simpler details and processes (Score 2.0 content) and partial knowledge of the more complex ideas and processes (Score 3.0 content). Progressing The student demonstrates no major errors or omissions regarding the simpler details and processes but exhibits major errors or omissions regarding the more complex ideas and processes (Score 3.0 content). partially prove but reasoning has gaps, steps missing, incorrect reasoning, etc. recall theorems, definitions, and postulates fill out justification given a statement Concepts: Vertical Angles Angles created by parallel lines and a transversal Perpendicular Bisector theorems 1.5 The student demonstrates partial knowledge of the simpler details and processes (Score 2.0 content) but exhibits major errors or omissions regarding the more complex ideas and procedures (Score 3.0 content). Beginning With help, the student demonstrates a partial understanding of some of the simpler details and processes (Score 2.0 content) and some of the more complex ideas and processes (Score 3.0 content). - 0.5 With help, the student demonstrates a partial understanding of some of the simpler details and processes (Score 2.0 content) but not the more complex ideas and processes (Score 3.0 content). 0.0 Even with help, the student demonstrates no understanding or skill. -

## Resources

 Web Vocab