California Assessment of Student Performance and Progress (CAASPP) Math Practice Exam

How many degrees are in a right angle?

1. 90 degrees

2. 100 degrees

3. 180 degrees

4. 270 degrees

The correct answer is: 90 degrees

A right angle measures 90 degrees. This is a fundamental concept in geometry, where angles are classified based on their measure. A right angle is specifically defined as the angle that forms exactly a quarter of a complete circle, which encompasses 360 degrees in total. Understanding that a quarter of a circle is 90 degrees is crucial for many applications in mathematics, particularly in trigonometry and geometry, where right angles form the basis of various shapes and theorems, such as the Pythagorean theorem. In contrast, the other angles listed do not meet the definition of a right angle. A 100-degree angle is considered an obtuse angle, larger than 90 degrees but less than 180 degrees. An angle measuring 180 degrees is classified as a straight angle, which forms a straight line. Lastly, a 270-degree angle represents three-quarters of a circle and is categorized as a reflex angle, as it exceeds 180 degrees. Understanding these classifications helps in recognizing the unique properties of different angles in geometric contexts.