%
% triangle.m Demonstrating the loop and
% graphics interaction
%
function triangle_opposite(len)

%

c=50;
d=10;
len=50; % length
%
  x(1)=c;
  x(2)=x(1)+len/2;
  x(3)=x(2)-len;
  x(4)=x(1);
  %--------------------
  y(1)=d;
  y(2)=y(1)+len*sin(pi/3);
  y(3)=y(2);
  y(4)=y(1);
%
%

  for j=1:3   
    line([x(j) x(j+1)],[y(j) y(j+1)]);
    text(x(j),y(j),num2str(j));
  end % i