Similar or Congruent Reteach

Similar or Congruent, Enlargement or Reduction?

Your Favorite Math Game Show!

Congruent Shapes

• Same Shape (So, same angles)

• Same Size (So, same side lengths)

Similar Shapes

• Same Shape (So, same angles)

• Different Size (So, NOT same side lengths)

• Instead, side lengths are proportional (multiplicative relationship)

Multiple Choice

Similar or Congruent?

• Similar

• Congruent

Multiple Choice

Similar or Congruent?

• Similar

• Congruent

Multiple Choice

Similar or Congruent?

• Similar

• Congruent

Multiple Choice

Angle R is 90 degrees. What is the measure of angle R' ?

• 90

• 45

• 180

Enlargements

• A type of dilation

• The shape gets larger!

Reductions

• A type of dilation

• The shape gets _smaller

Multiple Choice

Enlargement or Reduction?

• Enlargement

• Reduction

Multiple Choice

Enlargement or Reduction?

• Enlargement

• Reduction

Multiple Choice

Enlargement or Reduction?

• Enlargement

• Reduction

Scale Factor

• The number your multiply the length of a figure by to make its image (copy).

• This does not affect angle measurements because angles stay the same!

Multiple Choice

If a AB measures 2 and the scale factor is 3, what would the measurement of A'B' be?

• 2

• 3

• 6

Multiple Choice

If a AB measures 4 and the scale factor is 1/2, what would the measurement of A'B' be?

• 1/2

• 2

• 4

• 8

Multiple Choice

If angle A measures 60 degrees and the scale factor is 2, what would the measure of angle A' be?

• 2

• 60

• 120

A little more review...

Multiple Choice

What is the scale factor? (What do you multiply by to get from the original to the copy) if the original is on the top?

• 1/3

• 1

• 3

• 9

Multiple Choice

What is the scale factor? (What do you multiply by to get from the original to the copy) if the original is on the bottom?

• 1/3

• 1

• 3

• 9

Multiple Choice

What is the length of the missing side x?

• 6

• 3

• 2

Great work today!