Scale Factor and Proportions Exam

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, some quantity. It is used to determine how much larger or smaller a figure is compared to another figure.

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 the larger figure by the length of the corresponding side of the smaller figure.

Front

What is a proportion?

Back

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

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the terms and then solve for the unknown variable.

Front

What does it mean if two figures are similar?

Back

Two figures are similar if they have the same shape but not necessarily the same size, and their corresponding angles are equal while their corresponding sides are in proportion.

Front

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

Back

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

Front

If the scale factor from ABCD to MNOP is 2/3, how do you find the length of a side in MNOP if a side in ABCD is 12 units?

Back

Multiply the length of the side in ABCD by the scale factor: 12 units * 2/3 = 8 units.

Front

What is the relationship between scale factors and area?

Back

The area of similar figures is proportional to the square of the scale factor.

Front

If a proportion is set up as 3/4 = x/16, how do you solve for x?

Back

Cross-multiply: 3 * 16 = 4 * x, which gives 48 = 4x. Then divide by 4 to find x = 12.

Front

What is the scale factor from a smaller triangle with sides 3, 4, 5 to a larger triangle with sides 6, 8, 10?

Back

The scale factor is 2, since each side of the larger triangle is twice the length of the corresponding side of the smaller triangle.