error: cannot find symbol

import java.util.Scanner;
class Rect{
    double l,h,z;
    public Rect(double l,double h,double z){
        this.l=l;
        this.h=h;
        this.z=z;
    }
    //在父类Rect中，定义求底面周长的方法length( )和底面积的方法area( )。
    public double length(){
        return 2*(l+h);
    }
    public double area(){
        return l*h;
    }
}
//定义父类Rect的子类立方体类Cubic，计算立方体的表面积和体积。其中表面积area( )重写父类的方法。
class Cubic extends Rect{
    public Cubic(double l,double h,double z){
        super(l,h,z);
    }
    public double v(){
        return super.area()*z;
    } 
    public double area(){
        return length()*z+2*super.area();
    }
}
//定义父类Rect的子类四棱锥类Pyramid，计算四棱锥的表面积和体积。其中表面积area( )重写父类的方法。
class Pyramid extends Rect{
    public Pyramid(double l,double h,double z){
        super(l,h,z);
    }
    public double area(){
        return (l*h+(Math.sqrt(z*z+(h/2)*(h/2))*l)+(Math.sqrt(z*z+(l/2)*(l/2))*h));
    }
    public double v(){
        return super.area()*z/3;
    }
}
public class Main{
    public static void main(String[] args){
        //在主程序中，输入立体图形的长(l)、宽(h)、高(z)数据，分别输出长方体的表面积、体积、四棱锥的表面积和体积
        Scanner sc=new Scanner(System.in);
        while(sc.hasNext()){
            double l,h,z;
            l=sc.nextdouble();
            h=sc.nextdouble();
            z=sc.nextdouble();
            if(l<=0||h<=0||z<=0)
            {
                System.out.println("0.00 0.00 0.00 0.00");
            }
            else{
                Cubic Cubic=new Cubic(l,h,z);
                Pyramid Pyramid=new Pyramid(l,h,z);
                System.out.printf("%.2f %.2f %.2f %.2f\n",Cubic.area(),Cubic.v(),Pyramid.area(),Pyramid.v());
            }
        }
    }
}
//Main.java:47: error: cannot find symbol
//            l=sc.nextdouble();
//                ^
//  symbol:   method nextdouble()
//  location: variable sc of type Scanner
//Main.java:48: error: cannot find symbol
//            h=sc.nextdouble();
//                ^
//  symbol:   method nextdouble()
//  location: variable sc of type Scanner
//Main.java:49: error: cannot find symbol
//            z=sc.nextdouble();
//                ^
//  symbol:   method nextdouble()
//  location: variable sc of type Scanner
3 errors

nextdouble();
->
nextDouble();
大写！！！！！