## Do Now_On the Plane.docx - Section 1: Do Now

# On the Plane - Coordinate Geometry Proofs

Lesson 8 of 10

## Objective: SWBAT use coordinate geometry to prove properties of triangles and lines.

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This section of Geo Proofs will continue to scaffold 2-column coordinate geometry proofs for students (MP 7) and will challenge students to complete these lengthy proofs while working in pairs (MP 1). You can extend this part of the lesson by removing the boxes and suggested steps for students, whereas, you can modify this further by providing students with more hints in the boxes (i.e. midpoint of MP, rather than just MP). Students can also present their work to their peers for critic and review (MP 3).

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#### Activity/Homework

*10 min*

Students will demonstrate their knowledge of using coordinate geometry to prove that triangles are isosceles and that two points form a perpendicular bisector (MP 7). This Activity is scaffolded for students but can be modified to challenge students.

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#### Exit Ticket

*10 min*

In this Exit Ticket, students will write steps to determine if 3 points form an isosceles triangle in text form to a sick student. This will help students to look for and make use of structure (MP 7) in completing this task - and will hopefully be able to use these steps to complete the homework.

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#### Triangle Proof Project

*5 min*

You can give students any extra time in class to work on their project. Students should be actively working on the filming and editing of their project at this point and you can give them a schedule of when they will be presenting.

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###### Prove It (Part 1)

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- UNIT 1: Introduction to Geometry: Points, Lines, Planes, and Angles
- UNIT 2: Line-sanity!
- UNIT 3: Transformers and Transformations
- UNIT 4: Tremendous Triangles
- UNIT 5: Three Triangle Topics
- UNIT 6: Pretty Polygons
- UNIT 7: MidTerm Materials
- UNIT 8: Circles
- UNIT 9: 3-D Shapes and Volume
- UNIT 10: Sweet Similar Shapes
- UNIT 11: Trig Trickery
- UNIT 12: Finally Finals

- LESSON 1: Time for Triangles
- LESSON 2: Time for More Triangles
- LESSON 3: SSS for Real
- LESSON 4: SAS-sy Triangles
- LESSON 5: AAS and ASA Fun
- LESSON 6: HL and More Practice with Proofs
- LESSON 7: Isosceles Triangles Forever
- LESSON 8: On the Plane - Coordinate Geometry Proofs
- LESSON 9: Overlapping Triangles
- LESSON 10: Tremendous Triangles Projects