Similar Triangles Warmup

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 criteria for triangles to be similar?

Back

Triangles are similar if their corresponding angles are congruent and the lengths of their corresponding sides are proportional.

Front

What is a scale factor in similar triangles?

Back

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

Front

If triangle A is similar to triangle B, and the scale factor is 3, what does this mean?

Back

It means that each side of triangle B is 3 times longer than the corresponding side of triangle A.

Front

How do you determine if two triangles are similar using angles?

Back

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

Front

What happens to the size of a figure when the scale factor is greater than 1?

Back

The figure becomes larger.

Front

What happens to the size of a figure when the scale factor is less than 1?

Back

The figure becomes smaller.

Front

If triangle ABC is similar to triangle DEF, and AB = 4 cm, DE = 8 cm, what is the scale factor?

Back

The scale factor is 2, since DE is twice the length of AB.

Front

What is the relationship between corresponding sides of similar triangles?

Back

The lengths of corresponding sides of similar triangles are proportional.

Front

If the scale factor from triangle A to triangle B is 1/2, what can you say about their areas?

Back

The area of triangle B is 1/4 the area of triangle A, since area scales with the square of the scale factor.