How to provide curvature to a line?

Lets we have three points having coordinates as follows:

A(0,0)

B(6,4.5)

C(12,4.5)

and we have to draw line between these three points. Its simple as it can be seen in the code. Now the point B got a displacement of x=0.46 and y= -1.79 and new coordinates of B becomes (6.46,2.71). Also it has rotation of -5.278*10^(-4) rad. Now how to draw the deflected shape is an issue, as am not getting how to give curvature (rotation). Is there any built function for doing this?

The actual and deflected shape picture has been also attached right below for consideration.

Thanks

% Original Shape
x=[0;6;12];    %% x coordinates
y=[0;4.5;4.5]; %% y coordinates 
plot(x,y,'g')  %% plotting

[darova]

I think some data is missing

[Ahmed Anas]

Take this distance as per your choice.. Just i want to know how to provide curvature to a line.

[darova]

I only see straight lines. Can you show curvature?

[Ahmed Anas]

You can see the difference between two lines, the grey line is straight while dashed red line is given curvature(rotation) at point B equal to -5.278(10^-4) rad.