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The Side Between

Part of the Congruence & Proof section of Coddy's Geometry journey. Lesson 19 of 60.

Two angles of a triangle sit at two corners, and exactly one side joins those corners. That side is the included side of the two angles. The other two sides each touch only one of them.

$Triangle ABC with one arc at A and two arcs at B$

Here the marked angles are at A and B, so the side between them is AB. Its name is made of the two vertices. This is the side version of the included angle from the SAS chapter, and the next rules depend on it.

Challenge

Two angles of triangle LMN are marked with arcs. Tap the side between the two marked angles, then press Check.

Try it yourself

$Find the right part on the figure$

Find the right part on the figure

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Congruence & Proof

2Congruent Triangles

Same Size, Same Shape What Congruence Gives Recap: Matching Parts

5ASA and AAS

The Side BetweenThe ASA Rule The AAS Rule ASA or AAS?Recap: ASA and AAS

8Proofs with Vertical Angles

Vertical Angles in Proofs The Bowtie Bowtie with ASA Linear Pairs in Proofs Recap: Vertical Angles

11Similarity Proofs

AA Similarity Two Right Triangles SSS Similarity SAS Similarity Similar, Then Find Recap: Similarity