The Question: Find the area of the region enclosed by the graph of $|x-60|+|y|=|\frac x4|$.
What I know: Because of all the absolute values I only need to find one side of the graph of this equation, the positive side. The equation can be rewritten as $y=|\frac x4|-|x-60|$, where $y≥0$. How do I proceed?
Note: I have read the official solution for this problem, but I did not get how they found the vertices of the triangles.