In commerce, liquid oxygen is classified as an industrial gas and is widely used for industrial and medical purposes. Liquid oxygen is obtained from the oxygen found naturally in air by fractional distillation in a cryogenic air separation plant.
Lesson Summary. An acute angle is any angle smaller than 90 degrees. A right angle is an angle that measures 90 degrees. It doesn't matter how much smaller the angle is than 90 degrees; as long as it's smaller, it's acute. To unlock this lesson you must be a Study.com Member.
A triangle must be either acute, right, or obtuse. It also has three interior angles that always total 180 degrees. Because a right triangle has a right angle (exactly 90 degrees), the sum of its two remaining angles must be 90 degrees. These two angles are therefore inferred to be acute. The same holds true for an obtuse triangle, since it has an obtuse angle (measuring more than 90 degrees) that makes the sum of its two other angles be less than 90 degrees. No triangle has only one acute angle, or it wouldn't be a triangle.