The appearance of a triangle may indicate what type of triangle it is, but the best way to determine a type of triangle is to look at the angles of them.
For example, 30/60/90 or 45/45/90. These are acute right triangles, as they have a 90 degree angle in them.
Now, if we did 60/60/60, that would be an equilateral triangle, as all sides are the same length, and all angles are the same.
I hope this helps!
