While this figure is elegant in its way, it has a little bit too much going on for the beginning student. $
Multiply all three by the same ratio $\frac{1}{\cos x}$ we will get the side lengths of the similar triangle.
$(1,\tan x, \sec x)$
All of the "co" functions are "flipped" across the line $x=y$
![enter image description here](
Relating these figures to the first one, I will point out that these are congruent triangles.
![enter image description here](