Home » Articles » Blog » Proof – Sum of Measures of Angles in a Triangle are 180 Proof – Sum of Measures of Angles in a Triangle are 180 January 9, 2020 Bruce Wright 34 Articles, Blog Previous: Wide Angle HD Security Camera (180 Degree Lens) 1080p AHD CCTV Next: Messy Makeup Trivia ft. Jeffree Star & Tati About The Author Bruce Wright 34 Comments SuCKeRPunCH187 says: September 22, 2011 at 4:24 pm is there a name for this proof? Reply wmy says: October 14, 2011 at 1:44 am @SuCKeRPunCH187 Pythagorean theorem. Reply Sangram Musale says: May 1, 2012 at 10:45 am no!! there is no name for this proof Reply Rosalina4eva2gether says: June 19, 2012 at 7:26 pm Pythagorean theorem is only for right triangles Reply Sam Rockwell says: January 31, 2013 at 9:43 am يابن اللعيبه! Reply Yura Vuzaver says: July 23, 2013 at 11:11 pm Nah! .I did -20 lbs in 1 week.More here hawght.so#6nbNj41 Reply Andriy Kornoza says: July 31, 2013 at 3:19 pm Wow! .I did -40 lbs in 2 month.Visit hawght.so#b4TshQ1 Xa79MBTIOnqssdlJH Reply Jamie Park says: September 12, 2013 at 11:23 pm Triangle Angle Sum Theorem Reply Robert Hickman says: September 23, 2013 at 7:15 pm Why is it needed to say 'from both sides' in this context? Reply Broken Heart Jayy says: January 14, 2014 at 1:12 am i still dont get why me why me why me im so stupid Reply A M says: December 31, 2014 at 4:05 pm the vid gliched Reply Markalos says: February 25, 2015 at 2:58 am The Pythagorean theorem is a squared+b squared=c squared. It's used to measure right triangles sides lengths. E.g. A=3 B=4 C=5 Reply Rachel Rodabaugh Suvorov says: February 16, 2016 at 7:32 pm Well. That was unnecessarily convoluted and inefficient.Here is the easier way. Label the angles along the top line above the triangle, left to right, a, b, and c. Since they form a line, their sum is 180. Angles a and c are congruent to the triangle's lower right and left angles, respectively, because of the parallel lines theorem. Angle b is congruent to the to angle at the top of the triangle because they are vertical angles. So the triangle consists of three angles congruent to a, b, and c, which we know add up to 180. Therefore the triangle has 180 degrees. Reply TheFallen Hero says: May 3, 2016 at 11:48 pm it doesnt help you on notihng Reply Joe Blobber says: June 1, 2016 at 11:59 pm couldn't someone just add the angles inside the triangles and be done with it? Reply justin Bieber says: July 1, 2016 at 3:33 pm this guyz thing is trash Reply Savannah Vasquez says: October 14, 2016 at 4:17 am I don't understand how he explains how to do it Reply Jeon Jaeun says: March 7, 2017 at 1:15 pm caus hugo cant understand math ge is stupid booo Reply Keyur Kumbhare says: March 29, 2017 at 2:42 pm I am 17. Today, I got to know why is the sum of interior angles of a triangle is 180 Reply Sonali Taphare says: April 16, 2017 at 8:32 am gud to understand Reply Sohyla Hanout says: April 26, 2017 at 11:51 pm That was helpful Reply Sohyla Hanout says: April 26, 2017 at 11:52 pm Something i didnt heat from the top section of the comments Reply why tho? cause i said so says: May 4, 2017 at 3:12 am that was a waste of my time Reply chen adam says: June 4, 2017 at 7:36 am what what does the word 'argument' actually??? the things or issue we're talking about?? Reply The Slenderman says: June 29, 2017 at 10:11 am This is a little hard .The method we studied in school is easier . Reply JJG Games says: September 15, 2017 at 8:04 pm that was good Reply Biggus Dickus says: December 1, 2017 at 7:23 am That is really neat. Reply ujjwal gon says: December 14, 2017 at 5:09 pm Hai Reply Sombo Chea says: March 23, 2018 at 6:41 pm He's not on the triangle sum theorem yet. He's just explaining things differently before the sum theorem in his next videos. Man people don't watch how he teach in each of his videos. Stop acting smarter than the teacher. Go make your own videos. Reply Yousaf Sheraz says: April 21, 2018 at 8:06 pm You are complicated Reply Ananya Rahmani says: May 19, 2018 at 9:35 am you are a master of mathematics.now the only thing i see on youtube is khan academy Reply mywebjunks says: August 12, 2018 at 6:09 pm Found this video while teaching my son about this. Not sure if talking about x+y from 3:53 is nessesary. Confusing. After proved x == 'x', he can easily say angle C is equal to the angle next y, called 'z'. 'x' + y + 'z' =180, therefore A+B+C=180. Reply Joker Toker says: November 3, 2018 at 12:09 am Hey, when you do, "x+y+? = 180", where do we get the 180 from? Seems like the whole proof is dependent on the 180. I assume it is from a circle, since that half of a circle and can been seen in the drawing. I ask because what is the proof that circle is 360 degrees? Seems like a number was chosen and not a real proof to prove that a circle is 360 degrees and nothing else. Can I get some clarity on this. Reply Loneamaruq says: August 1, 2019 at 5:42 pm Ah yes, The Tostitos Method™. Very nice! Maximum crunchitude achieved! Reply Leave a Reply Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Save my name, email, and website in this browser for the next time I comment.