First notice the unit circle has a radius of 1.
Click and drag the slider for α. Note the size of α in degrees and in radians. (Although we wrote the word radians, it should NOT be written. There is no unit with radians.)
The ANGLE α is on the x-axis. The ANGLE α is the LENGTH OF THE ARC in the unit circle for the angle α in degrees. Read this sentence until you understand it. It is critical.
The value of the tangent function of the angle α is the height of triangle divided by the width of the triangle, i.e. the y-coordinate of T divided by the x-coordinate of T.

Rounded to 3 decimal places, how much is α=? What is the α in degrees? Which is on the x-axis of the function in the graph above?
Rounded to 1 decimal place, how much is α=? What is the α in degrees? Which is on the x-axis of the function in the graph above?
What is the ratio of the y-coordinate to the x-coordinate of the point T when α=? So what is ? Find this point on the graph of the function.
What is a decimal approximation for the coordinates of this point? Can you see that the scale of the graph is 1:1?
(I use the points (0,0), (0.75,1) and (1.5,∞) as my approximation when drawing the first half cycle of tan(x). Can you see why?)