//四边形
public class Quadrilateral {
//四个边
private int left_side
private int top_side
private int right_side
private int bottom_side
public Quadrilateral() {
}
public Quadrilateral(int left_side,int top_side,int right_side,int bottom_side) {
this.left_side = left_side
this.top_side = top_side
this.right_side = right_side
this.bottom_side = bottom_side
}
//求周长
protected int perimeter() {
return left_side+top_side+right_side+bottom_side
}
public int getLeft_side() {
return left_side
}
public void setLeft_side(int left_side) {
this.left_side = left_side
}
public int getTop_side() {
return top_side
}
public void setTop_side(int top_side) {
this.top_side = top_side
}
public int getRight_side() {
return right_side
}
public void setRight_side(int right_side) {
this.right_side = right_side
}
public int getBottom_side() {
return bottom_side
}
public void setBottom_side(int bottom_side) {
this.bottom_side = bottom_side
}
}
package test
//长方形
public class Rectangle extends Quadrilateral {
//高
private int height
//宽
private int width
public Rectangle() {
}
public Rectangle(int width,int height) {
this.width = width
this.height = height
}
@Override
protected int perimeter() {
return (2*width)+(2*height)
}
public int getHeight() {
return height
}
public void setHeight(int height) {
this.height = height
}
public int getWidth() {
return width
}
public void setWidth(int width) {
this.width = width
}
}
package test
//正方形
public class Square extends Rectangle {
//边长
private int side
public Square() {
}
public Square(int side) {
this.side = side
}
public int getSide() {
return side
}
public void setSide(int side) {
this.side = side
}
@Override
protected int perimeter() {
return 4*side
}
}
package test
public class Main {
public static void main(String[] args) {
//==========基本实例化
Quadrilateral q = new Quadrilateral(1,2,1,2)
System.out.println(q.perimeter())
Rectangle r = new Rectangle(1,2)
System.out.println(r.perimeter())
Square s = new Square(3)
System.out.println(s.perimeter())
//==========基本实例化
//==========多态实例化
Quadrilateral obj = new Quadrilateral(1,2,1,2)
System.out.println(obj.perimeter())
obj = new Rectangle(1,2)
System.out.println(obj.perimeter())
obj = new Square(3)
System.out.println(obj.perimeter())
//==========多态实例化
}
}
挣点分是真不容易
四个角为直角，四条边都相等。1、两组对边平行，且一角90度。
2、四边相等且一角为90度。
3、两个角90度，一组对边平行且相等。
4、对角线相等并且互相垂直平分。
你这题目太坑爹了！万一输入的四个点有三个以上在一条直线上怎么办？是不是还要给你写个验证？三角形面积公式你知道吧？把四个点两两之间距离求出来，找出最长的一条边，这个边把四边形化成两个三角形，再套用三角形面积公式相加就行了！哥哥我赖的动手，哪里不会可以再问我！
