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 Angle-Angle (AA) similarity criterion?

Back

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

Front

What is the Side-Side-Side (SSS) similarity criterion?

Back

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

Front

What is the Side-Angle-Side (SAS) similarity criterion?

Back

If one angle of a triangle is equal to one angle of another triangle and the sides including these angles are in proportion, then the triangles are similar.

Front

What is the sum of the angles in a triangle?

Back

180 degrees.

Front

If two angles of a triangle are 45° and 55°, what is the measure of the third angle?

Back

80°.

Front

What are complementary angles?

Back

Two angles that add up to 90 degrees.

Front

What is the relationship between the sides of similar triangles?

Back

The ratios of the lengths of corresponding sides are equal.

Front

If triangle ABC is similar to triangle DEF, and the length of side AB is 4 cm and side DE is 8 cm, what is the ratio of their sides?

Back

1:2.

Front

If two triangles are similar, how do their areas compare?

Back

The ratio of their areas is the square of the ratio of their corresponding sides.