Dilations
Similarity
Random
Rotation
Dilations pt. 2
100
True or False? Dilations always make a figure smaller.
False
100
What is true about congruent figures?
Same size and shape.
100
What is another transformation that will be the same as a 180-degree rotation?
reflect over the x and y axis.
100
The sum of all interior angles, a triangle will always equal this number.
180^o?
100
True/False
Dilations increase the measure of angles.
False
200
A dilation might change the size of a figure's side lengths but never the _______.
angles
200
Any one or more of these moves can be used to prove similarity. (list at least two moves)
1) Translations
2) Rotations
3) Reflections
4) Dilations
200
What day is the Chapter 4 Test?
Wednesday
200
What is the rule for a 90-degree counterclockwise
(x,y) --> (-y,x)
200
True/False, Explain why
Dilations ALWAYS increase the length of line segments or figures.
False, a dilation less than 1 may result in a smaller side length
300
Dilations always produce ___________ figures.
similar
300
True/False, explain why...
Triangle D has 90 degree, 30 degree, and 60 degree angles. Triangle E has all 60 degree angles. They are similar.
False, need to have the same angle measure.
300
The slope of this line.
2/3
300
What is the rule for a 180 degree rotation counterclockwise?
(x, y) --> (-x,-y)
300
You have two similar triangles. Triangle MNK has the following side lengths: MN = 2 units, NK = 5 units and MK = 3 units. Triangle MNK has been dilated to get Triangle M’N’K’. If you know that the length of M’N’ = 10 units, then the lengths of N’K’ and M’K’ are ______ and _______.
What are 25 and 15?
400
What do we need when describing dilations?
Scale Factor
400
True or false: Similar figures are always congruent.
False. Similar figures are sometimes congruent
400
Who do the BEE Seahawks play tomorrow?
McCook Central!
400
What is the rule for a 270-degree rotation counterclockwise?
(x, y) --> (y, -x)
400
If a figure has coordinates S (-4, -2), T (-3, 1) and U (-2, -2), what would the new coordinates be if it was dilated by 3, with (0,0) being the center of dilation?
What is S’ (-12, -6), T’ (-9, 3), and U’ (-6, -6)?
500
How will dilating a figure with a scale factor of 1/3 change a figure?
It will make the figure 3 times smaller from the center of dilation (or reduced/smaller figure)
500
Dilations can result in a congruent and similar figure if their scale factor is this number.
1 or -1
500
The slope of a line is a number we can calculate using at least ____ points on the line?
2
500
What happens when you dilate a figure by a scale factor of -1?
You do a 180-degree turn or reflect over the x and y axis.
500
If a figure has coordinates A (-6, -12), B (-4, 4) and C (-6, -10), what would be the new coordinates of C if the figure was dilated by 1/2?
What is (-3, -5)?