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 criterion for triangle similarity?

Back

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

Front

What is the SSS criterion for triangle similarity?

Back

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

Front

What is the SAS criterion for triangle similarity?

Back

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

Front

How do you set up a proportion for similar triangles?

Back

By comparing the ratios of the lengths of corresponding sides.

Front

If triangle ABC is similar to triangle DEF, and AB = 4, AC = 6, and DE = 8, what is the length of DF?

Back

DF = 6 (using the proportion 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

How can you determine if two triangles are not similar?

Back

If none of the criteria (AA, SSS, SAS) are satisfied, the triangles are not similar.

Front

In a scale drawing, if a gymnasium is 96 feet long and 75 feet wide, and the length on the blueprint is 5.5 inches, how do you find the width on the blueprint?

Back

Set up a proportion: 96/75 = 5.5/x, solve for x to find the width.

Front

What is a scale factor in similar triangles?

Back

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