Scale Factors and Area

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 the original.

Front

How do you calculate the area of a rectangle?

Back

Area = length × width.

Front

If a rectangle has an area of 72 sq. cm and is reduced by a scale factor of 1/8, what is the new area?

Back

18 sq. cm.

Front

What is the relationship between scale factor and area?

Back

The area of a shape changes by the square of the scale factor. If the scale factor is k, the new area = original area × k².

Front

What is the scale from the drawing to the actual stop sign if it is 1 in.: 6 in.?

Back

The scale indicates that 1 inch on the drawing represents 6 inches in reality.

Front

If a wall is 3 cm on a blueprint with a scale of 1 cm: 5 m, what is the actual length of the wall?

Back

15 meters.

Front

What does it mean if a drawing has a scale factor of 3/5?

Back

It means the drawing is 3/5 the size of the original image.

Front

How do you find the actual dimensions of a scaled copy?

Back

Multiply the original dimensions by the scale factor.

Front

If Lee wants to use a scale factor of 4 to create a scale copy, what are the dimensions if the original dimensions are length: 2 in., height: 1.5 in.?

Back

Length: 8 in., Height: 6 in.

Front

What is the area of a rectangle with a length of 10 cm and a width of 5 cm?

Back

Area = 10 cm × 5 cm = 50 sq. cm.