7.2 Similar Triangles

Front

What are similar triangles?

Back

Triangles that have the same shape but may differ in size. Their corresponding angles are equal, and their corresponding sides are in proportion.

Front

What is the AA similarity criterion?

Back

If two angles of one triangle are equal to two angles of another triangle, then the triangles are similar (AA∼).

Front

What is the SSS similarity criterion?

Back

If the corresponding sides of two triangles are in proportion, then the triangles are similar (SSS∼).

Front

What is the SAS similarity criterion?

Back

If two sides of one triangle are in proportion to two sides of another triangle and the included angles are equal, then the triangles are similar (SAS∼).

Front

What is the Side Splitter Theorem?

Back

If a line is drawn parallel to one side of a triangle, it divides the other two sides proportionally.

Front

If triangle ABC is similar to triangle DEF, and AB = 6, DE = 9, what is the ratio of their areas?

Back

The ratio of their areas is (AB/DE)² = (6/9)² = 4/9.

Front

How do you find the length of a side in similar triangles?

Back

Use the proportion of corresponding sides. If triangle ABC is similar to triangle DEF, then AB/DE = AC/DF.

Front

What is the relationship between the angles of similar triangles?

Back

The corresponding angles of similar triangles are equal.

Front

If two triangles have one angle equal and the sides including that angle are in proportion, what can be concluded?

Back

The triangles are similar (SAS∼).

Front

What is the scale factor in similar triangles?

Back

The ratio of the lengths of corresponding sides of two similar triangles.