Similarity and Scale Drawings

Front

What does it mean for two figures to be similar?

Back

Two figures are similar if they have the same shape but not necessarily the same size. Their corresponding angles are equal, and the lengths of their corresponding sides are proportional.

Front

How do you find the missing side of a similar figure?

Back

To find the missing side of a similar figure, set up a proportion using the lengths of the corresponding sides of the similar figures.

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, some quantity. In the context of similar figures, it is the ratio of the lengths of corresponding sides.

Front

If the scale factor is 2, what does that mean?

Back

If the scale factor is 2, it means that the dimensions of the new figure are twice as large as the dimensions of the original figure.

Front

How do you convert a scale drawing measurement to actual distance?

Back

To convert a scale drawing measurement to actual distance, multiply the measurement by the scale factor.

Front

What is the actual distance if a scale drawing shows 3 inches and the scale is 1 inch = 300 miles?

Back

The actual distance is 900 miles (3 inches x 300 miles/inch).

Front

What is the relationship between the sides of similar figures?

Back

The lengths of corresponding sides of similar figures are in proportion to each other.

Front

What happens to the area of a figure when it is dilated?

Back

When a figure is dilated by a scale factor of k, the area of the figure is multiplied by k².

Front

If a model is built at a scale of 5 in:25 ft, how do you find the actual size from the model size?

Back

To find the actual size, multiply the model size by the scale factor (5 in = 25 ft, so 1 in = 5 ft).

Front

What is dilation in geometry?

Back

Dilation is a transformation that changes the size of a figure but not its shape. It can make a figure larger or smaller.