Proving Triangles are Similar - YourTeacher.com - Geometry Help

For a complete lesson on proving triangles are similar, go to http://www.yourteacher.com - 1000+ online math lessons featuring a personal math teacher inside every lesson! In this lesson, students learn the following theorems related to similar triangles. If an angle of one triangle is congruent to an angle of another triangle, and the lengths of the sides that include each angle are in proportion, then the triangles are similar (Side-Angle-Side Similarity Theorem, or SAS Similarity Theorem). If the lengths of the sides of two triangles are in proportion, then the triangles are similar (Side-Side-Side Similarity Theorem, or SSS Similarity Theorem). Students are then asked to determine whether given triangles are similar based on these theorems.

Category:

Education

Tags:

• similar
• triangle
• triangles
• proofs
• sas
• sss
• similarity
• theorem
• theorems
• prove
• math
• proof

[clarkispotamia]

better than my math teacher.

[MajesticJeeL]

her voice is so boring

[ExtremelyDevout]

Her voice is so monotone but all the yourteachermathhelp videos are so simple and to the point that it doesnt even matter

[TheMysweetypie]

THAT WAS A GREAT HELP! THANKS FOR POSTING THIS.. Im in my early highschool life and Geometry is already giving me so many problems. :)))

[TheNarniafan04]

tnx for the help...God Bless

[lttlldl]

The triangles in part c) are NECESSARILY SIMILAR the moment she define angle M and T as an obtuse angle with a constant value (100 degrees). I don't understand why the lesson ignored trigonometry knowledge. Perhaps they were just careless when they decide to put in a number.

[130Y]

@SPBingo In a way, yourteachermathhelp is correct, so long as you find a common ratio for the sides, mathematically speaking, you can say that they are similar.

Well, thats what I thought anyways :) Usually if they have some sort of ratio between them, then nearly always, it will be the answer.

[SPBingo]

the part b) is wrong. The proportionality should be demonstrated between corresponding sides which has not bee done in this video. The triangles in part b are not similar.

[BlitzAceX]

...Man. I am going into psychiatry (that doesn't look right lol) so I know I need alot of biology and basic math...but I am taking geometry to just be safe and I am continuing with math but wow! My math teacher can't explain this at all!!!!! She says the same thing every time....the sad thing is, I will never have to use this

[BlitzAceX]

I have a test on Developing proofs and all the Postulates and Theorems (SSS SAS AAS ASA) of Ch. 4 for Geometry coming up. Thank you for this so much and wish me luck!!