Similar Polygons and Triangles

Front

What are similar polygons?

Back

Polygons that have the same shape but not necessarily the same 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, then the triangles are similar.

Front

What is the SSS criterion for triangle similarity?

Back

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

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, then the triangles are similar.

Front

If ΔPRQ ∼ ΔDEF, and the length of side PQ is 30 and side EF is 48, what is the scale factor from ΔPRQ to ΔDEF?

Back

Scale factor = EF / PQ = 48 / 30 = 1.6 or 8/5.

Front

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

Back

Set up a proportion using the lengths of the corresponding sides of the similar triangles.

Front

What is the scale factor of ΔABC to ΔDEF if the sides are in the ratio 3:5?

Back

The scale factor is 3/5.

Front

If the height of a tree is represented in a triangle, how can you find it using similar triangles?

Back

Use the properties of similar triangles to set up a proportion based on the corresponding heights and bases.

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 a scale factor of 5/6, what does this mean?

Back

It means that for every 5 units in the first triangle, there are 6 units in the second triangle.