编写一个 python 程序来计算圆的面积。
def area_of_circle(radius): 
 
    # 计算圆的面积 
    PI = 3.14
    area = PI * (radius * radius) 
      
    # P打印区域 
    print("The area of the circle is: %.2f" %area) 
      
# 驱动函数 
radius = float(input(" ENTER THE RADIUS OF CIRCLE: "))
area_of_circle(radius)