@brett1479 : So if I'm understanding correctly, what we have here is a 1-dimensional input space, which allows you to put the whole feature space on the x-axis, and a 2-parameter model because we have an intercept?
Why not just make the intro question exactly this -- We have x in reals and y in reals and we want to fit an affine function h(x) = theta_0 + theta_1 x. Otherwise there's a lot the person has to know to make sense of the pics, I think.