Proportions/Similar Figure Review (Accel. PreAlgebra)

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, a quantity. It is used to determine the size of similar figures.

Front

If the scale factor is greater than 1, what happens to the figure?

Back

The figure is enlarged.

Front

If the scale factor is less than 1, what happens to the figure?

Back

The figure is reduced.

Front

How do you find the missing side of similar figures?

Back

Use the proportion of the corresponding sides to set up an equation and solve for the missing side.

Front

What is the relationship between the sides of similar figures?

Back

The corresponding sides of similar figures are in proportion.

Front

If ΔDEF is similar to ΔABC and the scale factor is 2/1, what does this mean?

Back

It means that each side of ΔABC is twice the length of the corresponding side of ΔDEF.

Front

How do you set up a proportion to solve for a missing value?

Back

Set up a ratio of the known sides and set it equal to the ratio of the unknown side.

Front

In a recipe, if you increase the amount of one ingredient, what must you do to the other ingredients?

Back

You must increase the other ingredients in the same proportion to maintain the recipe's balance.

Front

What is the formula for finding the scale factor between two similar figures?

Back

Scale Factor = Length of a side of the new figure / Length of the corresponding side of the original figure.