Proof - Sum of Measures of Angles in a Triangle are 180

Proof that the sum of the measures of the angles in a triangle are 180

[mywebjunks]

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.

[rviiz]

you are a master of mathematics.now the only thing i see on youtube is khan academy

[nbthtpt]

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.

[MarkalosCap]

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

[KeyurKumbhare]

I am 17. Today, I got to know why is the sum of interior angles of a triangle is 180

[trubz]

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.

[oxygen]

اتوقع انه اسهل لو طابق زوايا قاعدة المثلث x و الزاوية الاخرى التي على يمينها مع الزوايا المطابقة لها في L كزوايا متطابقة على شكل حرف z بعدين جمعها كلها كزاوية مستقيمة والزاوية المستقيمة قياسها 180 اذا لا علموني ممكن في شي انا فاهمة غلط

[roberthickman]

Why is it needed to say 'from both sides' in this context?

[joeblobber]

couldn't someone just add the angles inside the triangles and be done with it?

[chenadam]

what what does the word 'argument' actually??? the things or issue we're talking about??

[savannahvasquez]

I don't understand how he explains how to do it

[Perc_A_Cent]

i still dont get  why me why me why me im so stupid 

[Rosalinaevagether]

Pythagorean theorem is only for right triangles

[sohylahanout]

Something i didnt heat from the top section of the comments

[wolffy]

Can someone please explain to me what the ---- he just explained

[muhammedanish]

This is a little hard .The method we studied in school is easier .