How do we identify transformations?

The 4 types of transformations are Rotations, Dilation, Reflection and Translation
Translation:
Every point is moved the same distance in the same direction.
Reflection:
Figure is flipped over a line of symmetry.
Rotation:
Figure is turned around a single point.
Dilation:
An enlargement or reduction in size of an image.
TRANSLATION:

Definition:  A translation (notation ) is a transformation of the plane that slides every point of a figure the same distance in the same direction.

Translations in the Coordinate Plane:

In the example below, notice how each vertex moves the same distance
 in the same direction.

In this next example, the "slide" (translation) moves the figure
7 units to the left and 3 units down.

DILATION

Example 1:

PROBLEM:  Draw the dilation image of triangle ABC with the center of  dilation at the origin and a scale factor of 2.OBSERVE: Notice how EVERY coordinate of the original triangle has been multiplied by the scale factor (x2). HINT: Dilations involvemultiplication!

http://www.regentsprep.org/Regents/math/geometry/GT3/Ldilate2.htmREFLECTION:

The reflection of the point (x, y) across the line y = x  is the point (y, x).       or       The reflection of the point (x, y) across the line y = -x  is the point (-y, -x).     or

http://www.regentsprep.org/Regents/math/geometry/GT3/Ldilate2.htm

http://www.regentsprep.org/Regents/math/geometry/GT2/Trans.htm

http://www.regentsprep.org/Regents/math/geometry/GT1/reflect.htm