Geometry Similarity of Triangles

Is Line BC parallel to Line DE?

• Yes, because the sides are proportional creating similar triangles

• No, because the sides are not proportional therefore the triangles are not similar

Triangle DEF is formed by connecting the midpoints of the sides of Triangle ABC. The lengths of DEF are shown. What are 2 things you know for sure about side BC?

• BD is perpendicular to DE

• BC is parallel to DF

• BA is 8 units

• BC is 8 units

Given AC = 6, what sequence of transformations takes triangle AED to Triangle ABC?

• Dilate Triangle ADE using Center A and scale factor 1/2, then reflect over Line AD

• Dilate Triangle ADE using Center A and scale factor 2, then reflect over Line AC

• Rotate Triangle ADE clockwise around center A, then dilate by scale factor 3/2

• Reflect Triangle ADE over Line AD, then dilate using center E by scale factor 3/2

Find the length of DF, or state what additional information is needed to determine this length.

• To determine DF, we need the perimeter of both triangles

• To determine DF, we need the length of DE

• DF = 7

• DF = 5

What is the similarity statement for the triangle pair?

The triangles are similar, find AE. Hint: Redraw as 2 triangles.

The two triangles are similar.

Solve for x. 

Which theorem or postulate shows that these triangles are similar?

• AA

• SAS

• SSS

• Not Similar

Are these triangles similar? If yes, write a similarity statement and determine if it is by SSS, SAS, or AA. Show all work.