Gradient of small differences

This is an introductory activity showing how the straight line gradient tends towards the gradient of the tangent at small approximations. This illustration will serve as a visual before using First Principles to derive gradient of a curve.
Gradient of 2 points A and B can be observed on the red line shown. Tangent of a point A can be observed on the blue line shown. What happens to the gradients of the lines when you drag the point B closer towards A?