Dilations
What is the definition of a dilation?
To make a figure bigger or smaller.
Triangle A has angle measures of 70°, 60° and 50°.
Triangle B has angle measures of 60°, 50°, 70°.
Are these triangles similar ?
Yes, they have at least 2 congruent angles.
What is the term we use to help us find the slope of a line?
Rise over Run
True or False: A dilation changes the shape of a figure.
False
Simplify this slope:
25 / 50
1/2
Segment AB is 4 centimeters. Point P is the center of dilation. After a dilation with a scale factor of 6, how long is the image of AB ?
24 centimeters
Triangle A has angle measures of 60°, 60° and ______°.
Triangle B has angle measures of 30°, 50°, ________°.
Are these triangles similar ?
The missing angles are 60° and 100°
The triangles are not similar because they don't have at least 2 congruent angles.
What is the slope of a line that rise 2 and runs 1?
run/rise = 2/1 = 2
All of the sides ∆ABC are 3 cm and ∆GFE is the image of ∆ABC AND side are 33. What is the scale factor?
11
Simplify this slope: 18/3
6
True or False: Dilations of an angle are congruent to the original angle.
True
Triangle A has angle measures of 80°, 75° and ______°.
Triangle B has angle measures of 25°, 80°, ________°.
Are these triangles similar ?
The missing angles are 25 and 75.
Yes, the triangles have at least 2 congruent angles.
Find the slope of the line passing through (2,4) and (6,10)
(y2 - y1)/(x2 - x1) =
(10 - 4) / (6-2) = 6/4 = 3/2
Name 3 types of rigid transformations.
Rotation, Translations and Reflections
Simplify this Slope:
4/16
1/4
After a dilation, a 6 inch line turns in 54 inch line. What is the scale factor ?
9
Triangle J has angle measures of 45°, 90° and ______°.
Triangle K has angle measures of 30°, 90°, ________°.
Are these triangles similar ?
Missing angles are 45 and 60.
No, these triangles are not similar because they do not have at least 2 congruent angles.
Find the slope of the line passing through (-3,-1) and (1,3)
(y2 - y1)/(x2 - x1) =
(3 - (-1)) / (1 - (-3)) = 4/4 = 1
If my point is on (2,4) and it translated 5 units to the right. What is the new point?
(7, 4)
Multiplying by 1/2 is the same as dividing by what number?
2
Segment CD measures 36 inches. After a dilation with a scale factor of 1/2, how long is the image of CD ?
18
Triangle Y has angle measures of 100°, _____ and ______°.
Triangle Z has angle measures of 30°, ______°, ________°.
Are these triangles similar ?
It Depends on the Angles You Chose. (Up to the Teacher to Decide)
Find the slope of the line passing through (-2, 4) and (2 ,0)
(y2 - y1)/(x2 - x1) =
(0 - 4) / (2 - (-2)) = -4/4 = -1
If my point is on (6,2) and it translated 6 units down. What is the new point?
(6, -4)
Multiplying by 1/4 is the same as dividing by what number?
4