求园柱体的表面积和体积
第一题：public class Trianglele { Point p1 = new Point(); Point p2 = new Point(); Point p3 = new Point(); void setTri(double x1, double y1, double x2, double y2, double x3, double y3) { this.p1.x = x1; this.p1.y = y1; this.p2.x = x1; this.p1.y = y2; this.p3.x = x3; this.p3.y = y3; } double Circumference(Trianglele t) { double line1, line2, line3; line1 = Math.hypot((t.p1.x - t.p2.x), (t.p1.y - t.p2.y)); line2 = Math.hypot((t.p2.x - t.p3.x), (t.p2.y - t.p3.y)); line3 = Math.hypot((t.p1.x - t.p3.x), (t.p1.y - t.p3.y)); return line1 + line2 + line3; } double Area(Trianglele t) { double line1, line2, line3; line1 = Math.hypot((t.p1.x - t.p2.x), (t.p1.y - t.p2.y)); line2 = Math.hypot((t.p2.x - t.p3.x), (t.p2.y - t.p3.y)); line3 = Math.hypot((t.p1.x - t.p3.x), (t.p1.y - t.p3.y)); double p = Circumference(t)/2; return Math.sqrt((p-line1)*(p-line2)*(p-line3)*p); } public static void main(String[] args) { Trianglele t =new Trianglele(); t.setTri(0, 0, 0, 3, 4, 0); System.out.println("三角形周长："+t.Circumference(t)); System.out.println("三角形面积："+t.Area(t)); }}class Point { double x, y;} 第二题:public class Trianglele { Point p1 = new Point(); Point p2 = new Point(); Point p3 = new Point(); Trianglele(double x1, double y1, double x2, double y2, double x3, double y3) { this.p1.x = x1; this.p1.y = y1; this.p2.x = x1; this.p1.y = y2; this.p3.x = x3; this.p3.y = y3; } double Circumference(Trianglele t) { double line1, line2, line3; line1 = Math.hypot((t.p1.x - t.p2.x), (t.p1.y - t.p2.y)); line2 = Math.hypot((t.p2.x - t.p3.x), (t.p2.y - t.p3.y)); line3 = Math.hypot((t.p1.x - t.p3.x), (t.p1.y - t.p3.y)); return line1 + line2 + line3; } double Area(Trianglele t) { double line1, line2, line3; line1 = Math.hypot((t.p1.x - t.p2.x), (t.p1.y - t.p2.y)); line2 = Math.hypot((t.p2.x - t.p3.x), (t.p2.y - t.p3.y)); line3 = Math.hypot((t.p1.x - t.p3.x), (t.p1.y - t.p3.y)); double p = Circumference(t)/2; return Math.sqrt((p-line1)*(p-line2)*(p-line3)*p); } public static void main(String[] args) { Trianglele t =new Trianglele(0, 0, 0, 3, 4, 0); System.out.println("三角形周长："+t.Circumference(t)); System.out.println("三角形面积："+t.Area(t)); }}class Point { double x, y;} 第三题：public class Cylinder { double radius,height; public static void main(String[] args) { Cylinder c = new Cylinder(); System.out.println("圆柱体体积："+c.Volume(10, 5)); } double Volume(double r,double h) { return 3.14*r*r*h; } } ?