RIGHT: the triangle must have one side that is 90°, which looks like a corner. ACUTE: Two (or more) angles of the triangle must be less than 90 degrees OBTUSE: One angle of the triangle must be greater than 90 degrees.
You would look at the angles. If it is larger than a right angle (90 degrees), it is obtuse. If it is smaller that a right angle it will be acute. Hope this helps!
