A dilation is a reduction or an enlargement of an object. If the scale factor is less than 1, then the dilation is a reduction. If the scale factor is greater than 1, then the dilation is an enlargement.

An example of using an enlargement is when a builder constructs a house using a blueprint.

Architects and builders use dilations and similar figures to obtain the correct measurements to create structures.

floor plan of house

A builder uses a scale factor greater than 1 to create an enlargement when constructing a house. If an architect were creating the blueprint of a house that has already been built, she would use a dilation. However, the dilation would be a reduction since it would have a scale factor of less than 1.

The measurements on the blueprint are the dimensions of actual rooms. In each case, the width is the first number, and the length is the second number. (width x length)

width of blueprint bedroom over width of actual bedroom width of blueprint bedroom width of actual bedroom = 0.25 ft over 8 ft 0.25 ft 8 ft

(Note: the dimensions are in feet!)

Interactive exercise. Assistance may be required. Use the floor plan and your knowledge of ratios and proportions to drag the correct answer to the correct blank. Use your finished results to answer the questions that follow.