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## Geometry (all content)

### Course: Geometry (all content)>Unit 2

Lesson 8: Sal's old angle videos

# The angle game (part 2)

More examples of the Angle Game. Created by Sal Khan.

## Want to join the conversation?

• Who knows ALL the angles in the second problem?
• The straight line was formed from 122 and 58
(1 vote)
• At , Sal said X=50' but probably meant X=56'.
• he fixed it around there is a little note that pops up
• Is 0/0 undefined?
• In a fraction, if the zero is at the denominator and the numerator holds a real number or to make it simple any number except zero then,the division is possible and the quotient or your answer will become zero. E.g. 0/4=0.This division terminates after finding the answer.Well if we were to divide zero by zero then we would have to divide the each zero which comes as an answer by zero again.E.g. 0/0 = 0. this answer "0" is to be again divided by zero to find the answer again as the division is left incomplete. so again 0/0 = 0. So if you go on dividing zero by zero,the answer will always come zero.Even if we try this division a million times,the answer is always going to be 0.Hence,0/0 is undefined.
(1 vote)
• If we look clearly, a star is a figure which has a pentagon(a five-sided fig.) in the middle.And the sides of this pentagon form a base for 5 different triangles on each side of this pentagon.Well,my doubt regarding these triangles is are these triangles isosceles? or are they scalene?Please someone clarify my doubt.
• Unless stated, there is no reason to think they'd be isosceles. so your doubt is correct. Sal shows that the lower-left triangle is not isosceles at when he shows that none of the triangle's angles equal the other. If it was isosceles, two of the angles would be the same.
• I don't know about you guys, but that 86 degree angle on the second shape just doesn't look like 86 degrees
• Not all angles are drawn to scale. if you see a 90 degree angle, but there is no info on the page that explicitly tells you it is a right angle, it is not a right angle.
• "I already think I might have made a mistake some place in the addition." You think? Already? Yes Sal, X is 56. Heureka! I thought I would watch through the video and see if you pick that up. =) And you did Sal!

You know guys, if the great Sal can make mistakes so can everyone else! He did admit though that he sometimes makes mistakes in the addition before he actually made the mistake. So it's kind of interesting, as if his subconscious was doing what he was saying.

Personally I think making mistakes is part of the learning process so it's good he made the mistake and even better that he saw it and corrected it. I too often make mistakes just like this one, and I miss the extra points on tests. This shows why you always have to go over your results and see if it's feasible.
• Thoughtful commentary, Samir. Let's never stop making mistakes!
• So, a star could basically be 8 smaller triangles?