Which of the following angles is equal to 90 degrees?

The angle that is equal to 90 degrees is expressed as π/2 radians. In the context of circular and angular measurements, the relationship between degrees and radians is crucial.

To provide some context, a full circle is equivalent to 360 degrees, which is expressed as 2π radians. When you divide this circle into four equal parts, each part represents a quarter turn, or 90 degrees. In radians, a quarter turn is calculated as (2π radians) / 4 = π/2 radians.

Understanding this conversion is fundamental in GIS and various applications involving angular measurements, such as when calculating directions, bearings, or rotating features on a map. Hence, π/2 rad accurately represents a 90-degree angle, aligning perfectly with the definitions used in both geometry and GIS applications.