Question 986831
Not clear; no angle is directly across from the right angle.  The hypotenuse is directly across from the right angle.

The 20 unit bottom leg is either opposite your angle theta or is one of the sides holding your angle theta.


ASSUMING your bottom segment is the 20 unit leg, and right angle on the left, and your theta on the right, then:
{{{system(cos(theta)=20/25,sin(theta)=y/25, 20^2+y^2=25^2)}}}
and you can finish finding what you need.


DEFINITION:  {{{cot(x)=cos(x)/sin(x)}}}