help electomagnetic field with matlab

I need to draw a triangele inside a circle. the triangele need to be in the center.
the potenzial inside=100 and outside=0
R=80
a=40 width of triangele

this is my work in matlab but I can't defined the triangele in the center.


clear all;
s1=80;
close all;
s2=80;

radius=80;
dx=0.5;
%mx=(-s1/2):dx:(s1/2);
%my=(-s2/2):dx:(s2/2);
mx=(-20):dx:(20);
my=(-20):dx:(20);
int_pot=110;
ext_pot=10;
%V=zeros(s2/dx,s1/dx);
V=zeros(160,160)
%external triangel
%for i=s1/(2*dx):-1:0
% for j=0:(s2/dx)
% if ((s1/(2*dx))-i>j/2)
%ניסוי מס 1
for i=20:-1:0
for j=0:(40)
if (((20))-i>j/2)

V(j+1,i+1)=0;
else
V(j+1,i+1)=int_pot;%
end
end
end

%המשך ניסוי
for i=(20):(40)
for j=0:(40)
if (i-(20)>j/2)
V(j+1,i+1)=0;
else
V(j+1,i+1)=int_pot;%
end
end
end

%for i=(s1/(2*dx)):(s1/dx)
% for j=0:(s2dx)
% if (i-(s1/(2*dx))>j/2)
% V(j+1,i+1)=0;
% else
% V(j+1,i+1)=int_pot;%
%end
% end
%end
%vx=(-s1/2):dx:(s1/2);
%vy=(-s2/2):dx:(s2/2);
%[xx,yy]=meshgrid(vx,vy);
%xx_size=size(xx);
%bb=(radius^2)*ones(xx_size);

%[xxx,yyy]=meshgrid(vx.^2,vy.^2);
%[ix,iy]=find(bb>=yyy+xxx);

%
vx=(-s1):dx:(s1);
vy=(-s2):dx:(s2);
[xx,yy]=meshgrid(vx,vy);
xx_size=size(xx);
bb=(radius^2)*ones(xx_size);

[xxx,yyy]=meshgrid(vx.^2,vy.^2);
[ix,iy]=find(bb>=yyy+xxx);



%עיגול
length_xy=length(ix);
for k=1:length_xy
V(ix(k),iy(k))=ext_pot;%
end
size_v=size(V);
V2=V;
V3=V;
iter=80;
for q = 1:iter
for n = 2:(size_v(1) - 1)
for m = 2:(size_v(2) - 1)
if V2(n,m) == 2
V(n,m) = 0.25*(V(n+1,m) + V(n - 1,m) + V(n,m + 1) + V(n,m - 1));
end
end
end
end

[u,v]=gradient(V,dx);
[xxx,yyy]=meshgrid(vx,vy);

figure(1)
mesh(vx,vy,V);
figure(2);
imagesc(vx,vy,V);
figure(3);
contour(V,40);
figure(4);
quiver(xxx,yyy,u,v,1.5);



thank you.

tob draw triangle inside circle....you just need take care of distance...you put three points for triangle with shorter distance of diametre and place in the middle of circle..if you find problem..you can ask me

hi,

thank's for your helping.

the distance for triangle are "mx/my"
the distance for circle are vx/vy

and after this the triangle located in the corner.

if you can help me to make him in the center?

thank you again