Dilations and Similarity

What is Dilation?

• Dilation means to enlarge or reduce a shape

• Dilation means to flip over a line

• Dilation means two figures that look alike

• Dilation means to make a shape smaller

Tags

CCSS.8.G.A.3

A scale factor that is less than one means

• The pre-image will be enlarged.

• The scale factor should be subtracted from the coordinates.

• The image is larger than the pre-image.

• The pre-image will be reduced.

Tags

CCSS.8.G.A.3

A triangle has vertices with coordinates A(2,0), B(3, -1) and C(-2,-5). If the triangle is dilated by a scale factor of 3 with the origin as the center of dilation, what are the coordinates of C'?

• (1,-2)

• (-6,-15)

• (-2/3,-5/3)

• (-5,-8)

Tags

CCSS.8.G.A.3

Are these two figures congruent, similar or neither?

• Congruent

• Neither

• Similar

Tags

CCSS.HSG.CO.B.6

CCSS.8.G.A.2

State the coordinate of the image of point B (-10,-6) after a dilation with a scale factor of 1/2.

• (5,3)

• (20,12)

• (-20,-12)

• (-5,-3)

Tags

CCSS.8.G.A.3

If two figures are similar, the corresponding angles are...

• Congruent

• Supplementary

• Proportional

• Different

Tags

CCSS.HSG.CO.B.6

CCSS.8.G.A.2

Which scale factor would enlarge a figure?

• 3.5

• 0.5

• 1/3

• 5/8

Tags

CCSS.8.G.A.3

How does a dilation change the angles of a polygon?

• It changes by the scale factor.
• Dilations do not change the angles.
• It is impossible to answer this question.  The angles change unpredictably.
• The angles all change to larger angles.

Tags

CCSS.8.G.A.3

Solve for X.

• 2 ft
• 3 ft
• 4 ft
• 6 ft

Tags

CCSS.HSG.SRT.A.2

Definition: The figure before a transformation has occurred. 

• Pre-image
• Image
• Translation
• Reflection

Tags

CCSS.HSG.CO.A.2