 When figures have the same size and shape we say they are congruent.  In this lesson I will focus on congruent triangles.

 When trying to determine if two triangles are congruent, you need to make sure they have the same shape, and that the corresponding measurements and/or angles are the same.

30 o 90 o 60 o 7.5 m 13 m 15 m 7.5 m 13 m 15 m The corresponding parts, or parts of the triangle that correspond to one another, match. Therefore, these two triangles are congruent.

 You do not need to know all the measurements and/or angles of two triangles to determine if they are congruent.

 As long as you know two side lengths and an angle, all the side lengths, or even two angles and a side length, for each triangle, you can determine if two triangles are congruent.

 Two triangles which only have the same corresponding angles are not congruent.  Even if two triangles have the same corresponding angles, they can still have different side lengths.