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 dimensions in geometric figures.

Front

How do you calculate the perimeter of a rectangle?

Back

Perimeter = 2 * (length + width).

Front

If a rectangle has dimensions 3.5 in. x 5 in. and is enlarged by a scale factor of 2.5, what are the new dimensions?

Back

New dimensions = (3.5 in. * 2.5) x (5 in. * 2.5) = 8.75 in. x 12.5 in.

Front

What is the formula for the area of a rectangle?

Back

Area = length * width.

Front

If a rectangle has an area of 20 cm² and is enlarged by a scale factor of 3, what is the new area?

Back

New area = original area * (scale factor)² = 20 cm² * 3² = 180 cm².

Front

How do you find the scale of a drawing?

Back

Scale = actual length / drawing length.

Front

If a model of a flagpole has a scale of 1 in. = 4 ft, how tall is a model that measures 12 inches?

Back

Actual height = model height * scale factor = 12 in. * 4 ft/in. = 48 ft.

Front

What happens to the perimeter of a shape when it is enlarged by a scale factor of 4?

Back

The new perimeter is 4 times the original perimeter.

Front

If the original perimeter of a rectangle is 30 cm, what is the new perimeter after enlarging by a scale factor of 4?

Back

New perimeter = 30 cm * 4 = 120 cm.

Front

What is the relationship between scale factor and area?

Back

When a shape is enlarged by a scale factor, the area increases by the square of the scale factor.