The height of a tree is measured by means of a cross-staff as shown in the figure above. The horizontal bar \(DE\) is adjusted up or down until points \(D, F,\) and \(B\) are in a straight line. Measured on level ground, \(DE\) is \(1\frac12\) feet, \(EF\) is \(12\) feet, \(GE\) is \(5\) feet and \(GA\) is \(60\) feet. How tall is the tree?


A. \(20\frac12\, ft.\)

B. \(22\, ft.\)

C. \(24\, ft.\)

D. \(25\frac12\, ft\).

E. \(26\frac12\, ft.\)


Answer: D

Source: GMAT Prep