Triangle similarity: Definition, demonstrations and practice
Definition
Two triangles are similar if and only if they have the three pairs of angles congruent . Also, the equivalent sides must be proportional.
Similar triangles
Analysis 1
Change the positions of points A, B, C, A', B' or C'. What do you see regarding the value of the scale factor (similarity ratio)?
Analysis 2
Change the positions of points A, B, C, A ', B' or C 'so that k is equal to 1. What can you notice about the triangles?
1st Similarity Case: ANGLE-ANGLE SIMILARITY
Analysis 3
Are the following triangles Similar?
Analysis 4
Are the following triangles Similar?
2nd Similarity Case: Side-Angle-Side
Analysis 5
Are the following triangles Similar?
Analysis 6
Analysis 3
Are the following triangles Similar?
Analysis 7
Are the following triangles Similar?
Analysis 8
Are the following triangles Similar?
