AP Physics B Summer Webassign

I need help with the last question for my summer webassign. Unfortunately, I will be taking the math it is based off of while taking the Physics class, whereas everybody else has already taken it. So it would help if the work was shown.

An observer, whose eyes are 1.83 m above the ground, is standing 28.0 m away from a tree. The ground is level, and the tree is growing perpendicular to it. The observer's line of sight with the treetop makes an angle of 22.0° above the horizontal. How tall is the tree?

Take the initial height and add the horizontal distance multipled by the tangent of theta.

ans: 1.83 m + 28*tan(22) = 13.1 m (to 3 significant digits)

AP Physics B??? Have not done trigonometry???

Let the tree be taller than the observer by h m, then
h/28=tan22*=>
h=11.31m approximately.
The height of the tree=
1.83+11.3=13.14 m approximately.