Similarity, Dilations, and Volume Review

Identify the shape

Use the correct formula

r: radius (remember to divide by 2 if they give you the diameter)

h: height

B: area of the base (you have to find this separately first)

ABC is the pre-image (original)

A'B'C' is the image (after the dilation)

The figure gets bigger or smaller, based on a scale factor.

To find coordinates, multiply the original coordinate by the scale factor

Scale factor >1: enlargement

Scale factor <1: reduction

SSS: All pairs of corresponding sides are proportional (you set up the fractions and they all simplify to the same thing)

Remember to pair largest side with largest side and smallest side with smallest side

SAS: Two pairs of sides are proportional, and the angle IN BETWEEN them is congruent

AA: Two pairs of angles are congruent (meaning equal)

Remember you can add vertical angles

Also look for possible shared angles that would be congruent.

Pair up the sides that "go together"

Set up a proportional equation

Cross-multiply to solve for x