An angle less than 90˚ would be an acute angle. An obtuse angle is where the angle is more than 90˚. A right angle is where the angle is exactly 90˚ (there is a tiny square that. represents 90˚). A straight angle is a 180˚ angle.
Amy should have flip the numerator and the denominator of the second fraction before multiplying. She also used addition instead of multiplication for the numerators.
