IM Geo.3.9 Practice: Conditions for Triangle Similarity
What is the length of segment DF?
In triangle ABC, angle A is 35º and angle B is 20º.
Select all triangles which are similar to triangle ABC.
Decide whether triangles ABC and DEC are similar. Explain or show your reasoning.
Lin is trying to convince Andre that all circles are similar.
Help her write a valid justification for why all circles are similar.
Must these parallelograms be similar?
Explain your reasoning. 
Determine if each statement must be true, could possibly be true, or definitely can't be true. Explain or show your reasoning.
An equilateral triangle and a right triangle are similar.
A right triangle and an isosceles triangle are similar.
Quadrilaterals and are similar.
What is the scale factor of the dilation that takes to ?
The circle centered at Q is a scaled copy of the circle centered at R.
Find the scale factor.
Find the value of .