Similar Triangles Proportions

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 scale factor in similar triangles?

Back

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

Front

If two triangles are similar, how do you find a missing side length?

Back

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

Front

What is the relationship between the angles of similar triangles?

Back

The corresponding angles of similar triangles are equal.

Front

How do you determine if two triangles are similar?

Back

Two triangles are similar if they have two pairs of corresponding angles equal (AA criterion) or if the sides are in proportion (SSS or SAS criteria).

Front

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

Back

The scale factor is 2 (8/4).

Front

Solve for x: 3/10 = (2x + 4)/30

Back

x = 3.

Front

What is the proportion of the sides in similar triangles?

Back

The ratio of the lengths of corresponding sides is constant for similar triangles.

Front

If the scale factor from ΔDEF to ΔABC is 1/2, what does this mean?

Back

It means that each side of ΔDEF is half the length of the corresponding side in ΔABC.

Front

Find the missing side: If the sides of triangle A are 5, 7, and x, and triangle B is 10, 14, and 2x, what is x?

Back

x = 7.