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 (Angle-Angle) Postulate?

Back

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

Front

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

Back

Use the proportion of corresponding sides. If triangle A and triangle B are similar, then A1/A2 = B1/B2, where A1 and A2 are sides of triangle A, and B1 and B2 are sides of triangle B.

Front

If a triangle has sides of lengths 3, 4, and 5, what is the ratio of its sides?

Back

The ratio is 3:4:5.

Front

What is the SSS (Side-Side-Side) Postulate?

Back

If the corresponding sides of two triangles are in proportion, then the triangles are similar.

Front

If two triangles have a side length ratio of 2:3, what can be said about their similarity?

Back

They are similar if their corresponding angles are equal.

Front

A 10 ft tall tree casts a shadow of 5 ft. If a 2 ft tall flower casts a shadow of X ft, what is X?

Back

X = 1 ft (using the proportion 10/5 = 2/X).

Front

What is the SAS (Side-Angle-Side) Postulate?

Back

If two sides of one triangle are proportional to two sides of another triangle, and the included angles are equal, then the triangles are similar.

Front

If triangle ABC is similar to triangle DEF, and AB = 6 cm, DE = 9 cm, 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 determine if two triangles are similar using their angles?

Back

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