1）编写一个Java应用程序，

1）该程序中有3个类：Triangle、Circle和cone，分别用来刻画“三角形”、“圆形”和“圆锥体”。具体要求如下：

a) Triangle类具有类型为double的三个边长度以及周长属性；定义构造函数，返回周长和修改三个边的方法。另外，Triangle类还具有一个boolean型的属性，该属性用来判断三个属能否构成一个三角形。

b) Circle类具有类型为double的属性半径、周长和面积；定义设置半径，返回面积的方法。

c) Cone类具有Circle类型的底，double类型的高这两个属性，定义构造函数，计算圆锥体体积的方法。

-1) write a Java application,

1) The program has three categories: Triangle, Circle and cone, were used to characterize the "triangle", "circle" and "cone." Specific requirements are as follows:

a) Triangle class has three types of double edge length and girth property　define a constructor, returns three sides of the perimeter and modification methods. In addition, Triangle class also has a boolean type attribute, which is used to determine whether the three form a triangle.

b) Circle class with properties of type double the radius, circumference and area　definitions set the radius, the method returns the area.

c) Cone Circle class has a bottom type, double type high these two properties, the definition of a constructor, method of calculating the volume of a cone.