Scale Factor, Scale Copy, and Corresponding parts

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, a quantity. In geometry, it is the ratio of the lengths of corresponding sides of two similar figures.

Front

What does it mean for two triangles to be similar?

Back

Two triangles are similar if their corresponding angles are equal and the lengths of their corresponding sides are in proportion.

Front

If triangle ABC is similar to triangle XYZ, and the scale factor is 2, what is the relationship between the sides of the triangles?

Back

The sides of triangle XYZ are twice the length of the corresponding sides of triangle ABC.

Front

What is a scale copy?

Back

A scale copy is a figure that is similar to another figure, created by enlarging or reducing the original figure by a scale factor.

Front

How do you find the length of a side in a scale copy?

Back

To find the length of a side in a scale copy, multiply the length of the corresponding side in the original figure by the scale factor.

Front

What are corresponding parts in similar figures?

Back

Corresponding parts are the sides and angles of similar figures that match up with each other.

Front

If the scale factor from triangle DEF to triangle RST is 3, and the length of side DE is 5, what is the length of side RS?

Back

The length of side RS is 15 (5 x 3).

Front

What is the scale factor if triangle ABC has sides of length 4, 6, and 8, and triangle XYZ has sides of length 8, 12, and 16?

Back

The scale factor is 2 (each side of triangle XYZ is twice the length of the corresponding side of triangle ABC).

Front

If triangle ABC is a scale copy of triangle DEF, and the length of side AB is 10, what is the length of side DE if the scale factor is 0.5?

Back

The length of side DE is 5 (10 x 0.5).

Front

How can you determine if two figures are scale copies of each other?

Back

To determine if two figures are scale copies, check if their corresponding angles are equal and if the lengths of corresponding sides are proportional.