#5). In a triangle, the angles track the sides in some interesting ways.
-- If all of the sides are the same length, then
the angles are all the same size.
-- If two sides are the same length, then
two of the angles are the same size.
-- If the sides are all different lengths, then
all of the angles are different sizes.
#5). All of the sides are different lengths.
That's called a "scalene" triangle.
(You're supposed to know that by now.)
One of the angles is more than 90 degrees.
That's called an "obtuse" angle.
If a triangle has an obtuse angle in it, it can't have more than
one of them, and it's called an "obtuse triangle".
#6). All of the sides are different lengths.
That's called a "scalene" triangle.
(You're supposed to know that by now.)
All of the angles are less than 90 degrees.
Those are called "acute angles".
A triangle with three acute angles is called an "acute triangle".