HALF ANGLE

 

 

 

 

 

SMALL ANGLES

 

 

 

 

 

 

 

 

 

 

The figure above,  is a small angle subtended by XY centre O of a circle of radius r, the area of the sector OXY is

The line  is tangent to circle at Y and area of  is  we conspicuously note that Area of OXY< area of sector OXY<area of