Review on Scale Factor & Scale Drawings

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, some quantity. It is used to determine the ratio of the dimensions of a scale drawing to the actual object.

Front

How do you calculate the width of a scale drawing?

Back

To calculate the width of a scale drawing, use the formula: Width in drawing = Actual width / Scale factor.

Front

If the scale is 1 cm : 9 m, how many centimeters represent 54 meters?

Back

6 cm (54 m ÷ 9 m/cm = 6 cm).

Front

What happens to a figure when the scale factor is greater than 1?

Back

The figure is enlarged.

Front

What happens to a figure when the scale factor is less than 1?

Back

The figure is reduced.

Front

If the perimeter of a rectangle increases from 20 in to 80 in, what is the scale factor?

Back

4 (80 in ÷ 20 in = 4).

Front

What is the scale factor if a triangle is reduced to half its size?

Back

1/2.

Front

How do you find the actual length from a scale drawing?

Back

Multiply the length in the drawing by the scale factor.

Front

If a scale drawing uses a scale of 1 mm : 5 m, how long is a 10 mm drawing in actual meters?

Back

50 m (10 mm × 5 m/mm = 50 m).

Front

What is a scale drawing?

Back

A scale drawing is a representation of an object that is proportional to its actual size, using a specific scale.