Scale Factor and Scale Drawings

Front

What is a scale drawing?

Back

A scale drawing is a representation of an object or area that is proportionally reduced or enlarged to fit on paper, using a specific scale.

Front

What does scale factor mean?

Back

Scale factor is the ratio of the length in a scale drawing to the corresponding length in the actual object.

Front

If a scale drawing uses a scale of 1:100, what does this mean?

Back

It means that 1 unit on the drawing represents 100 units in reality.

Front

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

Back

Multiply the length in the scale drawing by the scale factor.

Front

What is the formula for the perimeter of a rectangle?

Back

Perimeter = 2(length + width).

Front

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

Back

New perimeter = 30 cm x 4 = 120 cm.

Front

How do you find the width of an object in a scale drawing?

Back

Use the scale to convert the actual width to the drawing width by dividing the actual width by the scale factor.

Front

If a tent is 6 feet wide in reality and the scale is 1 inch : 3 feet, how wide is it in the drawing?

Back

2 inches.

Front

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

Back

The scale factor is 1/2.

Front

How do you determine the scale factor from a scale drawing?

Back

Divide the actual length by the length in the scale drawing.