Question

Write an indirect proof proving only one angle of an obtuse triangle is greater than 90 degree. Medal!

Answer 1

Anyone?

Answer 2

Welcome to OpenStudy! Just to let you know, before I guide you through this is that it's against the CoC (Code of Conduct) to give direct answers.

Answer 3

Kk.

Answer 4

Ok, so basically, what is the sum of the angles in any triangle?

Answer 5

90?

Answer 6

No, in an equilateral triangle, where all the angles are 45 degrees, what is the sum of all the angles?

Answer 7

I'm not sure:/

Answer 8

Wait, I think I did something wrong...

Answer 9

Huh?

Answer 10

Nvm, instead of 45 degrees for each corner in an equilateral triangle, there's 60 degrees. If there's 3 corners in each triangle, what is the total degrees?

Answer 11

180..

Answer 12

So, the sum of angles for any triangle is 180 degrees.. A right angle is 90 degrees, so an obtuse angle is where there is more than 90 degrees in that angle. So, it's 91 or above. An obtuse triangle is a triangle that has one obtuse angle. It you take away 180 from 91, you get 89, and when you divide 89 into two groups (they don't have be even), it can't equal more than 90. Therefore, there's only one obtuse angle in an obtuse triangle.

Answer 13

Hope that helped!

Answer 14

Thanks dragonmaster917

Answer 15

Welcome!