How to fix this please?

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Sololearn
{
class Program
{
class Shape
{
private int dimensions;
public Shape(int dimensions)
{
this.dimensions = dimensions;
int[] parts = new int[dimensions+1];
}
public int[] parts;
public static Shape operator * (Shape P1, Shape P2) {
Shape P = new Shape(P1.dimensions+P2.dimensions);
for (int x=0; x<=P.dimensions; x++)
{
for (int y=0; y<=P1.dimensions; y++) { for (int z=0; z<=P2.dimensions; z++) { if (x==y+z) P.parts[x]+=P1.parts[y]*P2.parts[z]; }}
}
return P;
}
}

Answer 1

Save code in playground and share link here..
Don't redeclare parts in constructor.
parts = new int[ dimension+1]; // don't include type int[] again...
Use < instead <=.

Answer 2

static void Main(string[] args)
{
Shape seg = new Shape(1);
seg.parts = new int[] {2,1};
Shape squ = new Shape(2);
squ.parts = new int[] {4,4,1};

Shape prod = seg * squ;
}
}
}

Answer 3

Copy and see it.!