How to draw every type of triangle?

I was only able to generate a equilateral triangle with my code below;

%Triangle=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= 
sides = 3;
 t = (1/(2*sides):1/(sides):1)*2*pi-pi/3;
 b = User_input(3);
 x = b*sin(t)+5/8*xmax;
 y = b*cos(t)+3/4*ymax;
 fill(x,y,'black');

[Jan]

Notice that we cannot guess what you want to achieve and what "User_input(3)" is. So please edit the question and append more information.

Answer 1

[Image Analyst]

My response is in your duplicate question: http://www.mathworks.com/matlabcentral/answers/217638-how-do-i-insert-the-area-of-each-shape-in-the-centre-of-it#comment_287731