S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS ∆ ZYX, identify the pairs of congruent angles and the...

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Similar Polygons

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Congruent ≅ sides and angles are exactly the same. Similar ∼ angles are exactly the same but the sides are proportional Similar figures have a similarity ratio. This is the ratio of the lengths of two corresponding sides. The order in a ratio matters and it must be in the form of a simplified fraction.

Transcript of S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS ∆ ZYX, identify the pairs of congruent angles and the...

Page 1: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

Similar Polygons

Page 2: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

Warm Up1. If ∆QRS ∆ZYX, identify the pairs of congruent angles and the pairs of congruent sides.Solve each proportion.

2. 3.

Page 3: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

Congruent ≅ sides and angles are exactly the same.

Similar ∼ angles are exactly the same but the

sides are proportionalSimilar figures have a similarity ratio. This is the ratio of the lengths of two

corresponding sides. The order in a ratio matters and it must be in the

form of a simplified fraction.

Page 4: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

Figures that are similar (~) have the same shape but not necessarily the same size.

Page 5: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

A similarity ratio is the ratio of the lengths of

the corresponding sides of two similar polygons.

The similarity ratio of ∆ABC to ∆DEF is , or .

The similarity ratio of ∆DEF to ∆ABC is , or 2.

Page 6: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

1. Are the two polygons similar?

2. Find the similarity ratio of ABCD to EFGH.

3. Find the similarity ratio of EFGH to ABCD.

Page 7: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

1. What is the similarity ratio of the two similar polygons?

Find x and y.

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Page 8: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

True or false If two figures are congruent, they are always

similar.

If two figures are similar, they are always congruent.

The similarity ratio of congruent figures is 1 to 1.

Page 9: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.
Page 10: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.
Page 11: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.
Page 12: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

The following polygons are similar.Find the Similarity ratio of small to bigFind the value of x.

Page 13: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

Find the length of the model to the nearest tenth of a centimeter.

Page 14: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

Lesson Quiz: Part I1. Determine whether the polygons are similar. If so, write the

similarity ratio and a similarity statement.

2. The ratio of a model sailboat’s dimensions to the actual boat’s dimensions is . If the length of the model is 10 inches, what is

the length of the actual sailboat in feet?

3. Tell whether the following statement is sometimes, always, or never true. Two equilateral triangles are similar.

Page 15: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.

Homework

Page 16: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.
Page 17: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.
Page 18: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.
Page 19: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.
Page 20: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.
Page 21: S IMILAR P OLYGONS. Warm Up 1. If ∆ QRS  ∆ ZYX, identify the pairs of congruent angles and the pairs of congruent sides. Solve each proportion. 2. 3.