4.7 Scale Factor

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, some quantity. It is used to enlarge or reduce figures in geometry.

Front

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

Back

To find the scale factor, divide the length of a side of the larger shape by the length of the corresponding side of the smaller shape.

Front

If a triangle has sides of 3 cm, 4 cm, and 5 cm, and is scaled by a factor of 2, what are the new side lengths?

Back

The new side lengths will be 6 cm, 8 cm, and 10 cm.

Front

What does it mean for two shapes to be similar?

Back

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

Front

If the scale factor is 1/2, what happens to the size of the shape?

Back

The shape is reduced to half its original size.

Front

What is the scale factor if a rectangle's length is increased from 4 cm to 8 cm?

Back

The scale factor is 2.

Front

If a square has a side length of 5 cm and is scaled down by a factor of 1/5, what is the new side length?

Back

The new side length is 1 cm.

Front

How do you calculate the area of a shape when the scale factor is known?

Back

To find the area of a scaled shape, square the scale factor and multiply it by the area of the original shape.

Front

If the area of a square is 16 cm² and the scale factor is 3, what is the area of the new square?

Back

The area of the new square is 144 cm² (since 3² * 16 = 144).

Front

What is the relationship between the scale factor and the perimeter of similar shapes?

Back

The perimeter of similar shapes is proportional to the scale factor.