Congruent Triangles
 Similar and Congruent Figures
 Two geometric figures having the same shape and size are said to be congruent figures.
 Two geometric figures having the same shape, but not necessarily the same size, are called similar figures.
Example:
(1) All circles are similar.
(2) All equilateral triangles are similar.
(3) All congruent figures are similar. However, the converse is not true.
 Similarity of Polygons
Two polygons with the same number of sides are similar, if

 their corresponding angles are equal
 their corresponding sides are in the same ratio (or proportion)
 Two lines segments are congruent, if they are equal in length.
 Two angles are congruent, if they have the same measure.
 CPCT:
CPCT stands for Corresponding Parts of Congruent Triangles.
If ΔABC ΔPQR, then corresponding sides are equal i.e., AB = PQ, BC = QR, and CA = RP and corresponding angles are equal i.e., ∠A …
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