Question

A Quarter turn of a ray OA about O describes a _______angle

Answer 1

1. An angle whose measure is ${90}^0$ is called as right angle
2. And we know that a complete turn of a ray forms a circle
3. That means that the full angle will be of ${360}^0$
4. And Quarter of ${360}^0$ is ${90}^0$
5. Hence, a quarter-turn of a ray OA will describe a right angle