Why are scale factors needed in this lesson?
Dilations and proving similarity
True or false: Similar figures do NOT have congruent angles.
False
(BE)/(EC)=?/(FC)
DF
What is the definition of similarity
There exists a series of transformations that take one figure onto another
Find the scale factor from 4 units to 1 unit
1/4
What is true about the shape and size of similar figures?
same shape, different size
If two angles in one triangle are congruent to two angles in another triangle, then the two triangles are similar.
Angle-Angle Triangle Similarity Theorem
Pythagorean Theorem
a^2 + b^2 = c^2
Find the scale factor from 10 units to 15 units
3/2
Suppose △ABC ~ △JKL. What angle is congruent to ∠K?
∠B
(DB)/?=(BC)/(EC)
FE
Definition of Scale Factor in a dilation
The number you multiply by to dilate each point, also can tell proportions of each side lengths
Find the scale factor from 20 units to 8 units
2/5
Suppose △ABC ~ △JKL. What side is congruent to side JL?
side AC
These triangles are similar by ____.
Angle-Angle Triangle Similarity Theorem
the definition of Angle-Angle Triangle Similarity Theorem
In 2 different triangles have 2 corresponding and congruent angles, we can say that those 2 triangles are similar
Find the scale factor from 11 units to 4 units
4/11
What is the scale factor of △ABC to △XYZ?
4/3
(EC)/(CB)=(FC)/?
CD
Definition of Dilation
Transformation in which each point on a figure and changes its distance from a fixed point, by a scale factor.