A surveyor made the measurements shown in the diagram below.
What is the measure, in feet, of AB, the straight-line distance across the stream?

(D) 100


You must recognize similar triangles in the diagram and set up the correct proportion, which could be expressed as: \(\frac{A C}{E C}=\frac{A B}{E D}\)
Letting AB be represented by x and substituting the other measures from the diagram, the proportion is then solved for the unknown measure.
\(\frac{A C}{E C}=\frac{A B}{E D}\)becomes \(\frac{{40}}{{10}} = \frac{x}{{25}}\)
Cross-multiplying: 10x = 1000
Dividing by 10: x = 100
The final answer is 100 feet.

Visit our website for other GED topics now!