http://www.ck12.org Chapter 7. Similarity
7.4 AA Similarity
Here you’ll learn how to determine whether or not two triangles are similar using AA Similarity.
What if you were given a pair of triangles and the angle measures for two of their angles? How could you use this
information to determine if the two triangles are similar? After completing this Concept, you’ll be able to use AA
Similarity to decide if two triangles are similar.
Watch This
MEDIA
Click image to the left for more content.CK-12 Foundation: Chapter7AASimilarityA
Watch this video beginning at the 2:09 mark.
MEDIA
Click image to the left for more content.James Sousa:SimilarTriangles
MEDIA
Click image to the left for more content.James Sousa:SimilarTriangles by AA
Guidance
The Third Angle Theorem states if two angles are congruent to two angles in another triangle, the third angles
are congruent too. Because a triangle has 180◦, the third angle in any triangle is 180◦minus the other two angle
measures. Let’s investigate what happens when two different triangles have the same angle measures.