Yes there is an easier non-calculus method for obtaining the same result. It is based on the idea the three points define a unique circle. The three points are the top of the statue (A), the bottom of the statue (B) and the eye(s) of the observer (C). This circle is minimised, giving the best viewing angle when the horizontal line through C is tangential to the circle. This is easy to see when the diagram is draw. A few simple construction lines the set up two similar triangles from which the result is directly obtained.