Answer:
90 degrees is a right angle whoever your teacher is she is wrong.
Explanation:
An acute triangle has three angles that each measure less than 90 degrees. An obtuse triangle is a triangle with one angle that is greater than 90 degrees. this is what she might have meant
and this is some information on it
An obtuse angle has a measurement greater than 90 degrees but less than 180 degrees. However, A reflex angle measures more than 180 degrees but less than 360 degrees. So, an angle of 190 degrees would be reflex. Comment on Anthony Fritz's post “A 190 degree angle is not obtuse.