A Poster of Height 33 In $\theta$ Subtended at His Eye by the Poster Is as Large

Short Answer

A poster of height 33 in. is mounted on a wall so that its lower edge is 15 in. above the eye level of an observer. How far from the wall should the observer stand so that the viewing angle $\theta$ subtended at his eye by the poster is as large as possible (see figure - not drawn to scale)? Round your answer to the nearest integer.