（1）求一个6*6阶矩阵对角线元素之和。（2）实现打印数出有10个元素的浮点数组a中的最大值和最小值。（3）求面积。（4）产生两个小按钮。（5）程序的作用是用Math.random() 函数产生20个随机数。-(1) for a 6* 6 bands and the matrix of diagonal elements. (2) to achieve print a few out there are 10 elements in a floating-point group of maxim

java编程使用抽象类或借口计算三种几何图形的面积与周长，几何图形的尺寸自定-java programming using the abstract class or an excuse to calculate area and perimeter of the three geometry, the geometry of size custom