Similar Figures Using Proportions

Front

What are similar figures?

Back

Similar figures are shapes that have the same shape but may differ in size. Their corresponding angles are equal, and the lengths of their corresponding sides are proportional.

Front

What does it mean for two figures to be similar?

Back

Two figures are similar if their corresponding angles are equal and the ratios of the lengths of their corresponding sides are equal.

Front

How do you find the missing side of similar figures?

Back

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

Front

If triangle ABC is similar to triangle DEF, and AB = 4, DE = 8, what is the ratio of their sides?

Back

The ratio of their sides is 1:2.

Front

If two similar figures have a scale factor of 3, what does this mean?

Back

It means that every side of the larger figure is 3 times the length of the corresponding side of the smaller figure.

Front

Solve for x: If triangle ABC ~ triangle DEF and AB = 6, DE = x, and the scale factor is 2, what is x?

Back

x = 12.

Front

What is the scale factor?

Back

The scale factor is the ratio of the lengths of two corresponding sides of similar figures.

Front

If two similar rectangles have a length ratio of 3:5, what is the ratio of their areas?

Back

The ratio of their areas is 9:25.

Front

How do you set up a proportion for similar figures?

Back

To set up a proportion, write the ratio of the lengths of corresponding sides as a fraction and set it equal to the ratio of the lengths of the other corresponding sides.

Front

If the lengths of two similar triangles are in the ratio 4:7, what is the ratio of their perimeters?

Back

The ratio of their perimeters is also 4:7.