Geometric Proofs
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Objective
I can write a two-column proof to prove geometric theorems.
Part 1 of 4
Warm-up video
Khan Academy · 11:06Vetted channel
We don't generate video — this one is by Khan Academy on YouTube. The practice questions and exit ticket below were drafted by AI for this objective, and every question is editable in the teacher guide.
Part 2 of 4
Key concepts
3 concepts
- 1
A two-column proof includes a statement and a reason for the statement.
- 2
If three sides of two triangles are congruent, then the triangles are congruent by the side-side-side postulate.
- 3
If two triangles are congruent, then all of their corresponding angles are equivalent.
Part 3 of 4
Practice
3 questions
What is the purpose of a two-column proof in geometry?
In the video's proof, which congruence postulates were used to prove that segment AC is perpendicular to segment DB?
Part 4 of 4
Exit ticket
Quick comprehension check
“Given: AB ≅ CD, BC ≅ DA. Prove: ∠B ≅ ∠D using a two-column proof.”
Sample answer included in the free materials
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