Similar Triangle Proportions

Front

What are similar triangles?

Back

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

Front

What is the Triangle Proportionality Theorem?

Back

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

Front

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

Back

Use the ratio of the lengths of corresponding sides to set up a proportion and solve for the unknown length.

Front

If triangle ABC is similar to triangle DEF, and AB/DE = AC/DF, what does this imply?

Back

It implies that the ratios of the lengths of corresponding sides are equal.

Front

What is the scale factor in similar triangles?

Back

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

Front

If the scale factor of triangle ABC to triangle DEF is 2:3, what does this mean?

Back

For every 2 units in triangle ABC, there are 3 corresponding units in triangle DEF.

Front

How can you determine if two triangles are similar?

Back

By checking if their corresponding angles are equal or if the sides are in proportion.

Front

What is the relationship between the areas of similar triangles?

Back

The ratio of the areas of two similar triangles is equal to the square of the ratio of their corresponding side lengths.

Front

If triangle PQR is similar to triangle XYZ and PQ = 10 cm, XY = 15 cm, what is the ratio of their sides?

Back

The ratio of their sides is 10:15 or 2:3.

Front

What is a proportion?

Back

An equation that states that two ratios are equal.