D) Seven years ago, father was seven times as old as his son was. Three years hence, he will be three times as old as his son. Find their present age.​

In the diagram, points d and e are marked by drawing arcs of equal size centered at b such that the arcs intersect ba and bc. then, intersecting arcs of equal size are drawn centered at points d and e. point p is located at the intersection of these arcs. based on this construction, m , and m