Question 3 • TX-Mathematical Models with Applications A
The friend and the rock form similar triangles because sunlight creates the same angle for both shadows. Set up the proportion 5.5/18 = h/209.5. Solving gives h = (5.5 × 209.5)/18 ≈ 64.0 feet, so the rock is about 64 feet tall. The correct choice is 64 ft.
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