def getNormal(begin, center, end):
 centerMinusBegin = (center - begin).getNormalized()
 endMinusCenter = (end - center).getNormalized()
 return centerMinusBegin.cross(endMinusCenter)

def getNormal ( begin , center , end ) : centerMinusBegin = ( center - begin ) . getNormalized ( ) endMinusCenter = ( end - center ) . getNormalized ( ) return centerMinusBegin . cross ( endMinusCenter )
get normal .