Transformations are:

• Rotations: "turning" a shape a certain number of degrees

• Reflections: "flipping" a shape over a line of reflection

• Translations: "sliding" a shape a certain distance in a certain direction

Transformations are also called "rigid motions" because they do not change the object's size or shape - it just moves to a new location!

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Congruency

Two shapes are CONGRUENT if one can be "mapped" (matched up EXACTLY by moving it) onto the other shape using only rigid motions (transformations).

Congruent? YES!

The orange shape could rotate/turn and then translate/slide onto the blue one.

Congruent? NO!

The blue triangle is larger than the red triangle. They would not match up exactly.

Congruent? YES!

The shape on the left could reflect/flip and then translate/slide onto the right one.

When shapes are congruent, we identify the points, lines or angles that CORRESPOND to each other from the two shapes.

Who corresponds to who?

Here are a few...

• Vertex A corresponds to Vertex E

• Side BC corresponds to Side DF

• Angle C corresponds to Angle F