Shapes tutorial missing NumPy constant definitions

[ghost]

In the shapes tutorial, for the yellow lines, there are several places where constants are not defined as np.<constant>, even though they are inherited from NumPy. The code currently reads:

pointers = []
for i in range(8):
    pointers.append(Line(ORIGIN, np.array([cos(pi/180*360/8*i),sin(pi/180*360/8*i), 0]),color=YELLOW))

But needs to be fixed to:

pointers = []
    for i in range(8):
        pointers.append(Line(ORIGIN, np.array([np.cos(np.pi/180*360/8*i), np.sin(np.pi//180*360/8*i), 0]), color=YELLOW))

Where sin() and cos() have been fixed to np.sin() and np.cos(), and pi has been fixed to np.pi. Without it, the script doesn't compile properly (at least not for me).

Edit: I have posted a pull request. I can't link it to this issue because I don't have edit access, but I forked this repo and created a pull from a branch on my fork.