Unit 4 Similar Triangles: Proportions & Similar Polygons

Front

What are similar polygons?

Back

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

Front

How do you set up a proportion for similar triangles?

Back

To set up a proportion, compare the ratios of the lengths of corresponding sides of the triangles. For triangles ABC and DEF, if AB/DE = AC/DF, then the triangles are similar.

Front

If two triangles are similar, what can be said about their corresponding angles?

Back

The corresponding angles of similar triangles are equal.

Front

What is the relationship between the sides of similar triangles?

Back

The lengths of corresponding sides of similar triangles are in proportion.

Front

How do you find the height of an object using shadows?

Back

Use the proportion of the height of the object to the length of its shadow, and set it equal to the proportion of the height of another object to its shadow length.

Front

If a tree is 12 feet tall and casts a shadow of 9 feet, what is the height of a building that casts a shadow of 24 feet?

Back

32 feet (Set up the proportion: 12/9 = x/24).

Front

Back

x = 2.

Front

If two polygons are similar and one has a side length of 9, what is the corresponding side length of the other polygon if the ratio is 3:1?

Back

3 (Since 9/3 = 3).

Front

What is the value of x if the polygons shown are similar and the corresponding sides are in the ratio 11:9?

Back

11.

Front

Back

x = -7.25.