# Angular Sector

## Angular Sector

In a plane, a geometric figure defined by the union or the intersection of two half-planes whose boundaries intersect at a point O called the vertex of the angular sector.

• The radian measure of a salient angular sector is the real number $$a\in \left[ 0,\pi \right]$$.The radian measure of a re-entrant angular sector is the real number $$\left( 2\pi-a \right)$$ where $$a\in \left [ 0,\pi \right ]$$.
• The degree measure of a salient angular sector is the real number $$\beta \in \left [ 0,180 \right ]$$. The degree measure of a re-entrant angular sector is the real number $$\left ( 360-\beta \right )$$ where $$\beta\in\left [ 0,180\right ]$$.
• The gradient of a salient angular sector is the real number $$y \in \left [ 0,200 \right ]$$. The gradient of a re-entrant angular sector is the real number $$\left ( 400-y \right )$$ where $$y \in \left [ 0,200 \right ]$$.