90 in terms of pi please help

90 in terms of pi is .

Step-by-step explanation:

We know that ,

Degrees are a unit of angle measure. A full circle is divided into 360 degrees. For example, a right angle is 90 degrees. A degree has the symbol ° and so ninety degrees would written 90°. Another unit of angle measure is the radian.The radian is the SI unit for measuring angles, and is the standard unit of angular measure used in many areas of mathematics. The length of an arc of a unit circle is numerically equal to the measurement in radians of the angle that it subtends; one radian is just under 57.3 degrees.

We have to convert 90 in terms of pi i.e. degree to radians:

⇒

⇒

⇒

⇒

Therefore, 90 in terms of pi is .

C. a,b, and d are not numbers. they are expressions.