def sector_area(self, theta: float) -> float:
    'Returns the area of a sector of the circle which subtended angle theta(radians) at center.'
    return (((self.radius ** 2) * theta) / 2)
Returns the area of a sector of the circle which subtended angle theta(radians) at center.
def sector_area(self, theta: float) -> float:
    
    return (((self.radius ** 2) * theta) / 2)