Similarity Unit Review

Front

What is the scale factor in similar figures?

Back

The scale factor (k) is the ratio of the lengths of corresponding sides of two similar figures.

Front

How do you determine if two triangles are similar?

Back

Triangles can be determined to be similar using the AA (Angle-Angle), SAS (Side-Angle-Side), or SSS (Side-Side-Side) criteria.

Front

What does AA~ mean in triangle similarity?

Back

AA~ means that if two angles of one triangle are equal to two angles of another triangle, the triangles are similar.

Front

What does SAS~ mean in triangle similarity?

Back

SAS~ means that if two sides of one triangle are proportional to two sides of another triangle and the included angles are equal, the triangles are similar.

Front

What does SSS~ mean in triangle similarity?

Back

SSS~ means that if all three sides of one triangle are proportional to the three sides of another triangle, the triangles are similar.

Front

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

Back

k = \frac{DE}{AB} = \frac{8}{4} = 2.

Front

If the scale factor k = \frac{3}{4}, what does this imply about the lengths of the sides of the similar figures?

Back

It implies that for every 4 units in the original figure, the corresponding side in the similar figure is 3 units.

Front

What is the value of x if the sides of two similar triangles are in the ratio 2:5 and one side of the smaller triangle is 8?

Back

x = \frac{5}{2} \times 8 = 20.

Front

Find the missing side in similar triangles if one side is 12 and the corresponding side in the other triangle is 30.

Back

The missing side is 30.

Front

If triangle XYZ is similar to triangle PQR, and XY = 10, PR = 25, what is the scale factor k?

Back

k = \frac{PR}{XY} = \frac{25}{10} = \frac{5}{2}.