GEO 8.1 - Similar Polygons and Scale factors

Front

What are similar polygons?

Back

Polygons that have the same shape but may have different sizes. Their corresponding angles are equal, and the lengths of their corresponding sides are proportional.

Front

What is a scale factor?

Back

A number that describes how much a figure is enlarged or reduced. It is the ratio of the lengths of corresponding sides of similar figures.

Front

If triangle ABC is similar to triangle DEF with a scale factor of 2:1, what does this mean?

Back

It means that each side of triangle ABC is twice the length of the corresponding side of triangle DEF.

Front

How do you find the missing side of similar polygons?

Back

Set up a proportion using the lengths of the corresponding sides and solve for the missing length.

Front

If the sides of two similar triangles are in the ratio 3:5, what is the scale factor from the smaller triangle to the larger triangle?

Back

5/3.

Front

What is the relationship between the areas of two similar polygons?

Back

The ratio of their areas is the square of the ratio of their corresponding side lengths.

Front

If the scale factor of two similar figures is 1/4, what is the ratio of their areas?

Back

1/16.

Front

How do you determine if two polygons are similar?

Back

Check if their corresponding angles are equal and the lengths of their corresponding sides are proportional.

Front

If a triangle has sides of lengths 6 ft, 8 ft, and 10 ft, what are the lengths of the sides of a similar triangle with a scale factor of 1/2?

Back

3 ft, 4 ft, and 5 ft.

Front

What is the formula for finding the scale factor between two similar figures?

Back

Scale Factor = Length of a side of the first figure / Length of the corresponding side of the second figure.