Proportions and Scale Factor

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, some quantity.

Front

How do you find the scale factor between two similar figures?

Back

To find the scale factor, divide the length of a side of one figure by the corresponding length of the other figure.

Front

If a rectangle has a length of 4 cm and a width of 2 cm, what is the scale factor if the new rectangle has a length of 8 cm?

Back

The scale factor is 2.

Front

What is the relationship between proportions and cross-multiplication?

Back

In a proportion, cross-multiplication can be used to find an unknown value by multiplying the means and the extremes.

Front

If 3/4 = x/16, what is the value of x?

Back

x = 12.

Front

What does it mean for two figures to be similar?

Back

Two figures are similar if they have the same shape but not necessarily the same size.

Front

How can you determine if two ratios form a proportion?

Back

Two ratios form a proportion if their cross products are equal.

Front

If a model is built at a scale of 1:50, what does this mean?

Back

It means that 1 unit on the model represents 50 units in real life.

Front

What is the formula for finding the area of a rectangle?

Back

Area = length × width.