Common Core Geometry Unit 3 - Latest Information & Updates 2026

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In this lesson we look at different ways to prove that lines are parallel. We then incorporate these methods into longer proofs ...

In this lesson we will investigate what conclusions can be drawn about geometric figures based on what we are told (given) about ...

In this lesson we look at the SAS, ASA, and SSS Theorems for proving that two triangles are congruent. Simple proofs involving ...

The axioms of equality and congruence are discussed in this lesson along with their simple use in proof with both line segments ...

In this lesson we explain the idea of CPCTC reasoning in geometric proof. We will then use this reasoning in a variety of simple ...

We first prove the AAS Theorem for triangle congruence based on the ASA Theorem. We then use both theorems to investigate ...

In this lesson we review the major properties of parallel lines, such as alternate interior angles and corresponding angles being ...

In this lesson we examine basic addition and subtraction proofs with segment lengths and angles. We then use these in longer ...

Hello and welcome to another

Foreign hello and welcome to another

In this lesson we examine important characteristics about isosceles triangles and use rigid motions to prove these properties.

In this lesson we prove the hypotenuse-leg theorem for triangle congruence and then use it in a variety of proofs including ...