Similar Figures and Scale Factors

Front

What are similar figures?

Back

Figures that have the same shape but may differ in size. Their corresponding angles are equal, and their corresponding sides are proportional.

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6

Front

What is a scale factor?

Back

A number that describes how much a figure is enlarged or reduced. It is the ratio of the lengths of corresponding sides of similar figures.

Tags

CCSS.7.G.A.1

Front

If the scale factor from figure A to figure B is 1/2, what does this mean?

Back

Figure B is half the size of figure A.

Tags

CCSS.7.G.A.1

Front

How do you determine if two figures are similar?

Back

Check if their corresponding angles are equal and their corresponding sides are in proportion.

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6

Front

What does it mean for two figures to be congruent?

Back

Two figures that are the same shape and size, meaning all corresponding sides and angles are equal.

Tags

CCSS.8.G.A.2

Front

If triangle DEF is similar to triangle ABC with a scale factor of 2, what is the relationship between their side lengths?

Back

The side lengths of triangle ABC are twice as long as those of triangle DEF.

Tags

CCSS.HSG.SRT.A.2

Front

Find the missing side if the scale factor from triangle XYZ to triangle PQR is 3 and one side of triangle XYZ is 5.

Back

The corresponding side of triangle PQR is 15.

Tags

CCSS.7.G.A.1

Front

What is the scale factor from ΔDEF to ΔABC if the sides of ΔDEF are 4, 6, and 8 and the sides of ΔABC are 2, 3, and 4?

Back

The scale factor is 1/2.

Tags

CCSS.7.G.A.1

Front

If two triangles have sides of lengths 6 and 9, and 4 and 6, are they similar?

Back

Yes, because the ratios of the corresponding sides (6/4 = 3/2 and 9/6 = 3/2) are equal.

Tags

CCSS.HSG.SRT.A.2

Front

What is the relationship between the angles of similar figures?

Back

The corresponding angles of similar figures are always equal.

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6