Visualizing Tangent

Geometrically visualize the tangent ratio as a function of the angle in standard position.
1. Which line is TANGENT to the circle at x=1? 2. Drag "angle" slowly along the x-axis. Describe (very precisely and with pictures) what happens to the purple segment QA as the angle increases. 3. QA = sin(angle)/cos(angle). 
 WHY is this true? Explain your thinking with detail and pictures. 4. Turn on point T. 
 Drag the angle and observe the purple segment QA and the graph of y= tan x.
 Explain with detail and pictures the ways in which QA and the graph are related to each other.