Instructional Video
Sophia Learning

Sophia: Introduction to Geometric Proof

9th - 10th Standards
Explore the structure and how to complete a flow proof and a two-column proof.
Instructional Video
Sophia Learning

Sophia: Pythagorean Theorem Proof

9th - 10th Standards
Find the area of several figures to prove the Pythagorean theorem. Complete quiz to check understanding. [5:16]
Instructional Video
Khan Academy

Khan Academy: Triangles: Wrong Statements in Proofs Example 1

9th - 10th Standards
A video analyzing how to recognize wrong statements in a proof. [2:48]
Instructional Video
Khan Academy

Khan Academy: 3. Completing the Proof

9th - 10th
In this video we'll uncover the connection between the previous diagram and the rotation formulas. Repeat viewing suggested!
Instructional Video
Sophia Learning

Sophia: Proving or Disproving a Solution: Lesson 2

9th - 10th
In this lesson, students see how to find out whether or not a solution is correct or incorrect. It is 2 of 7 in the series titled "Proving or Disproving a Solution." [4:01]