Similar Triangles Proportionality Theorems

Calculate the length of DE.

• DE = 23 m

• DE = 24 m

• DE = 25 m

• DE = 26 m

Are lines a, b, and c parallel?

• Yes, because lines d and e cut lines a, b, and c proportionally.

• Yes, because they look parallel.

• No, because lines d and e did not cut lines a, b, and c proportionally.

• No, they don't look like they are parallel.

Determine if the pair of triangles are similar by applying the triangle similarity theorems and postulates.

• Similar; by AA

• Similar; by SAS

• Similar; by SSS

• Not Similar

Two triangles are similar if their corresponding angles are congruent, and their corresponding sides are in __________.

Tell whether the given pair of triangles are similar or not. If so, what triangle similarity theorem applied?

• Similar; by SAS Similarity Theorem

• Similar; by SSS Similarity Theorem

• Not Similar

• Similar; by AA Similarity Theorem

Tell whether the given pair of triangles are similar or not. If so, what triangle similarity theorem or postulate applied?

• Similar; by SSS Similarity Postulate

• Not Similar

• Similar; by SAS Similarity Postulate

• Similar; by AA Similarity Postulate

∆ABC ~ ∆PQR based on the figure below. Which of the following will support the similarity statement?

• AA Similarity Postulate

• SSS Similarity Theorem

• SAS Similarity Theorem

• AAA Similarity Theorem

The two triangles below are similar. Which of the following gives the correct statement of proportionality?

• 
• 
• 
• 

Tell whether the given pair of triangles are similar or not. If so, what triangle similarity theorem or postulate applied?

• Similar; by SAS Similarity Postulate

• Similar; by AA Similarity Postulate

• Similar; by SSS Similarity Postulate

• Not Similar

This theorem states that “If the lengths of the corresponding sides of two triangles are proportional, then the two triangles are similar."

• AA Similarity Postulate

• SAS Similarity Theorem

• ASA Similarity Theorem

• SSS Similarity Theorem