You can put this solution on YOUR website!
The vertical height of the tree and the horizontal shadow are the legs of a right triangle with a 36 degree angle at the end of the shadow.
The ratios of the lengths of the sides of right triangles are the trigonometric ratios. The one useful here is
The tangent of 36 degrees can be found through tables, calculators, or computer programs. You have to be careful because there are different units for measuring angles, so you have to make sure that you and your calculator (or table, or computer) are talking in the same units.
Since the shadow was adjacent to that angle and the tree height was across/opposite, --->
