How do you determine if a triangle is right based on the length of the sides?

Question

I have to tell whether a triangle is right or not based on the length of the sides i'm given and i'm drawing a blank on how to do that.

I think it's adding 2 of the sides and the sum has to be greater than the third side or something like that but i'm not sure. Can someone help me with this?

Answer 1

Pythagoras Theorem!

If

c²=a²+b²

where c is the hypotenuse (the longest side in the triangle)

and a and b are the other sides

Then that triangle is a right angled triangle

Answer 2

Use Pythagorean theorem. a^2 + b^2 = c^2

Square all 3 lengths. If any of the 2 added together equal the third then its a right triangle.

Or

the sum of 2 sides must be greate than the 3rd but this can get tricky.

Answer 3

If it's a right triangle there will be a right angle in the triangle...

http://www.mathopenref.com/images/triang...

right triangle

http://upload.wikimedia.org/wikipedia/co...

obtuse triangle

http://upload.wikimedia.org/wikipedia/co...

acute triangle

Answer 4

im pretty sure its some rule called the cosine rule or the sinerule... i dunno im learning this in maths at the moment too.  

Answer 5

Ask Pythag.

a^2+b^2=c^2

C is the hypo. (the longest side)

A and B are the other two sides

If you plug in and both sides are equal, than it is a right triangle.

Adding Two sides to equal more than the other side is only a proof of it being a triangle.