Question

how to determine if a triangle is right, acute, or obtuse given sides triangle
I have 18, 80, and 81
I know it's not right because
18 squared+ 80 squared is 6724
and 81 squared is 6561
I don't know how to decide whether it's acute or obtuse

Answer 1

Here's a good thing to remember with these problems

\(\large a^2 + b^2 = c^2\) would be a right triangle
\(\large a^2 + b^2 < c^2\) would be an obtuse triangle
\(\large a^2 + b^2 > c^2\) would be an acute triangle

Answer 2

So it's acute! thanks!

Answer 3

Indeed! And no problem :)