Congruent figures are two or more shapes that are the exact same size and shape. Think of identical twins or cookies cut out with cookie cutters.
Similar figures are two or more shapes that are the exact same shape, but are different sizes. Think of a blown up copy of a picture and the original or an adult bike compared to a child's bike.
Symmetry is when an object can be divided in half and the two sides end up being congruent, mirror images. An example would be a heart split down the center. Other types of symmetry exist, but we will just be dealing with reflectional symmetry. You can have more than one line of symmetry in an object. For example, the picture of the leaves below has more than one line of symmetry.
Other symmetry pictures.
Reflections are when a picture is flipped over a line to show the exact opposite image. The parts of the object the are close to the "mirror" will still be close on the other side, just opposite. Far parts will remain far.
Rotations are when a shape is turned. The actual shape/figure remains the same, but is turned to a new position. Often it will appear sideways or upside down.
Now it's here...