Dilations Part 1
What object did Ms. Yang compare the Center of Dilation to?
Name one thing that stays the same when a figure is dilated.
Shape
Angle measures
Proportionality of sides
What transformation creates similar figures?
Dilation
Slope measures the __________ of a line.
How many points on a line do we need to draw a slope triangle?
2
What thing did Ms. Yang compare the image to?
Shadow of the pre-image
How can you tell when a figure has been dilated?
The size of the figure changed
What does it mean for two shapes to be similar?
Same shape, different size
What kind of slope does a line going uphill have?
A positive slope
What is the equation we used to calculate the slope?
slope = height/base
What does a scale factor of 4 do to a figure during a dilation?
Makes the figure bigger by 4 times
What's the very first step we take when drawing dilations?
Find the center of dilation and put a point.
How is "similar" different from "congruent"?
Congruent means same shape, same size.
Similar means same shape, different size.
What does a slope of 0 mean?
The line is horizontal.
Line b has a slope triangle with base=5 and height=10. Find the slope of line b.
Slope = height/base = 10/5 = 2/1
Give me a scale factor that would make the figure smaller.
Any number less than 1 works
Examples: 1/2, 0.6, 3/4, 0.5
What's the second step we take when drawing dilations?
Draw the rays coming out from the center of dilation connecting each point of the pre-image
Name a shape that's always similar to each other.
Circles (always same shape, just bigger or smaller)
Equilateral triangles (All sides are always equal so same shape, just bigger or smaller)
Squares (All sides are always equal so same shape, just bigger or smaller)
Here are 6 lines and their slopes. Which line will be the steepest?
Line A: 10/2
Line B: 6/2
Line C: 1/2
Line D: 2/5
Line E: 6/1
Line E
Line m has a slope triangle with base=11 and height=20. What's the slope of line m.
slope = height/base = 20/11
The image is to the right of the pre-image after a dilation. Where is the center of dilation located at?
Left of the pre-image
Why do we draw the rays coming out from the Center of Dilation when drawing dilations?
The rays help us get a more accurate location of the image.
A dilation occurred. The image is similar AND congruent to the pre-image. What does that tell you about the scale factor?
The scale factor = 1.
What does an "undefined" slope look like?
A vertical line.
Line v goes through point (0,0) and (3,4). What's the slope of line v?
So slope triangle has height=4 and base=3
Slope = height/base = 4/3