*Learning Goal: Introduce proof structure in a non-math way and then transition towards proving parallel lines & transversal theorems.*

# Google Slides

- Link to Slides
- Taken from Ben Orlin

# Classwork

- Desmos Activity for Warm Up and Notes
- If paper is preferred, use the following:
- Warm Up
- Allowing 15 minutes for research worked well

- Notes
- Look at example proofs in Google Slides before moving to notes
- Also, the students can use this word bank to try some of the proofs

- Spiraling Practice

# Answers

# Standards

**Common Core**- HSG.CO.C.9 – Prove theorems about lines and angles. Theorems include: 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.

**TEKS**- G.4(A) – distinguish between undefined terms, definitions, postulates, conjectures, and theorems
- G.4(B) – identify and determine the validity of the converse, inverse, and contrapositive of a conditional statement and recognize the connection between a biconditional statement and a true conditional statement with a true converse
- G.6(A) – verify theorems about angles formed by the intersection of lines and line segments, including vertical angles, and angles formed by parallel lines cut by a transversal and prove equidistance between the endpoints of a segment and points on its perpendicular bisector and apply these relationships to solve problems