Compare and contrast the terms acute angle, obtuse angle, right angle, straight angle

Acute angle is less than 90 degrees, obtuse is more than 90, right angle is 90 exactly, and the straight angle equals 180 degrees.

They are all angles.
Acute: anything under 90 degrees
Obtuse: anything over 90 degrees
Right: 90 degrees exact
Straight: 180 degrees exact

Well to find if anything is dividable by 3 add up all the 2+6+3+4+1 which equals sixteen which is not divisbale by 3. the three trick works with all numbers 12..1+2=3 so it is dividable