Identify Congruent Triangles

Shapes that are exactly the same shape and size are congruent.

They could be rotated or reflected but they are still congruent.

 

 

All the rectangles above are congruent!

 

Triangles - Special Case

We have a set of rules which make a triangle congruent!

If these rules, apply then the triangles are congruent!

 

1) Three matching sides (SSS)

 

 

If all three sides are the same, then the angles will also be the same and the triangles are congruent.

 

2) Two matching sides and the angle between them (SAS)

 

 

This means the two sides and the angle between them.

If they are the same then the other side must be the same also.

 

3) Two matching angles and a corresponding side (AAS)

 

 

This means two corresponding angles and a corresponding side.

 

4) In a right-angled triangle, the hypotenuse and one matching side (RHS)

 

 

Obviously, the triangle has to be right-angled for this one.

 

Make a note of the four rules and we will look at some questions!