Triangle similarity review

Review the triangle similarity criteria and use them to determine similar triangles.

What are the triangle similarity criteria?


AA	Two pairs of corresponding angles are equal
SSS	Three pairs of corresponding sides are proportional
SAS	Two pairs of corresponding sides are proportional and the corresponding angles between them are equal

Want to learn more about the triangle similarity criteria? Check out this video.

Check your understanding

Problem 1

Which triangle is similar to triangle $A$ ??

Want to practice more problems like this? Check out this exercise for the AA criterion and this exercise for the SSS criterion.

Want to join the conversation?

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grace.mews
Posted 5 years ago. Direct link to grace.mews's post “i dont get most of this s...”
i dont get most of this stuff
Button navigates to signup pageComment on grace.mews's post “i dont get most of this s...”
(26 votes)
Answer
- KhanAcademy101
  Posted 5 years ago. Direct link to KhanAcademy101's post “Try to practice upon it a...”
  Try to practice upon it and you might get it, or just use khan academy's practice a lot. Hope it helps
  Comment on KhanAcademy101's post “Try to practice upon it a...”
  (23 votes)
meowcatmeow
Posted 7 years ago. Direct link to meowcatmeow's post “How can you tell the diff...”
How can you tell the difference between SAS and SSA? (Assume you had a problem and had to chose if it was sim. because of SAS or SSA, how would you figure it out?)
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(12 votes)
Answer
- Ezra
  Posted 4 years ago. Direct link to Ezra's post “SAS means that the angle ...”
  SAS means that the angle is in between the two sides in question. SSA means the angle is not in between.
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  (21 votes)
Martinez, Rayleen; 200807072
Posted 4 years ago. Direct link to Martinez, Rayleen; 200807072's post “The videos im watching is...”
The videos im watching is not adding up to the working you guys are giving me. Im so lost.
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(13 votes)
Answer
beauregard42
Posted a year ago. Direct link to beauregard42's post “Yo, man. This is how we d...”
Yo, man. This is how we do da thing. Firstly, if the triangles have 2+ matching corresponding angles, then it is similar. If it has side lengths that can be divided by a number, say X, and then match the side lengths of your other triangle, then it is similar. If it has 2 matching corresponding(see last sentence) sides, and the angle between these is the same, then it is similar. -Beauregard42. If this helps you, your welcome.
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(8 votes)
Answer
JAKE617
Posted 4 years ago. Direct link to JAKE617's post “Define Equation”
Define Equation
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(2 votes)
Answer
- Evan
  Posted 4 years ago. Direct link to Evan's post “An equation is a statemen...”
  An equation is a statement with an equals sign.
  
  So 3 + 5 = 8 and 5x + 12 = (x / 4) + 3 are both equations,
  but 24 * 9 and 3y ≥ x - 8 are not equations.
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  (13 votes)
Tim O
Posted a year ago. Direct link to Tim O's post “What other triangle simil...”
What other triangle similarity criteria can be used?
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(3 votes)
Answer
- annasusan.pra
  Posted a year ago. Direct link to annasusan.pra's post “I believe AA, SAS, and SS...”
  I believe AA, SAS, and SSS are the only triangle similarity theorems
  Comment on annasusan.pra's post “I believe AA, SAS, and SS...”
  (6 votes)
Michelle Banks
Posted 7 months ago. Direct link to Michelle Banks 's post “I thought I thought I wou...”
I thought I thought I would need a calculator for quiz 1,
But I got a 100% Without even trying.
*And I never did this before!*
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(4 votes)
Answer
- Lynn
  Posted 4 months ago. Direct link to Lynn's post “Good job!”
  Good job!
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  (2 votes)
natealcalde724
Posted a year ago. Direct link to natealcalde724's post “I hate geometry just beca...”
I hate geometry just because of this unit.
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(4 votes)
Answer
zachary.foret
Posted 2 years ago. Direct link to zachary.foret's post “These lessons do not expl...”
These lessons do not explain SSS similar triangles very well. What lesson would help me understand the basics?
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(2 votes)
Answer
- connormoorhouse51
  Posted a year ago. Direct link to connormoorhouse51's post “I suppose trying the Tria...”
  I suppose trying the Triangle Similarity postulates/criteria lesson, or going back and reading the articles and doing all of the practice problems may help you. Ultimately, in summary, the SSS similarity is used when every side can be multiplied by a constant to get the new side, for example, if AB/XY was 4, AC/AZ was 4, and BC/YZ was 4, it would be a SSS similarity because each value can be multiplied either by 4 or 1/4 (depending on which number is larger) which is defined as the constant. I hope this helps!
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  (4 votes)
djackson0094
Posted 3 years ago. Direct link to djackson0094's post “i don't get it sometimes”
i don't get it sometimes
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(3 votes)
Answer
- lily.m.2203
  Posted 3 years ago. Direct link to lily.m.2203's post “Is there anything I can d...”
  Is there anything I can do to help you?
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  (2 votes)