问题描述：
The circumference of a circle is directly proportional to the length of its radius,and its area is directly proportional to the square of the length of its radius.If the circumference of a circle is multiplied by 6,then its area is multiplied by ________需要翻译及解答最佳答案：
圆的周长与半径成比例,圆的面积与半径的平方成比例.如果周长扩大6倍,它的面积扩大多少倍?答：36倍