Download Similar Triangles

Similar Triangles
Two Triangles are similar if their corresponding (matching)
angles are equal and the ratio of their corresponding sides are
in proportion. A ratio is a comparison of two quantities.
One is an enlargement of the other. This means that the two
shapes will have the same angles and their sides will be in the
same proportion (e.g. the sides of one triangle will all be 3
times the sides of the other etc.).
The mathematical symbol used to denote similar is ! .
Similar triangles have the following properties:
• They have the same shape but not the same size.
• Each corresponding pair of angles is equal.
• The ratio of any pair of corresponding sides is the same.
The ratio is
1
2
Proving Similar Triangles
To show triangles are similar, it is sufficient to show that two
angles of one triangle are congruent (equal) to two angles of
the other triangle. (AA Rule)