Question 7 • TX-Pre-Calculus
The lighthouse and the two boats form an isosceles triangle with equal sides of length r and a 40° angle at the lighthouse. Splitting the triangle in half gives a right triangle with opposite side 15 miles and angle 20°, so sin(20°) = 15/r and r = 15/sin(20°) ≈ 43.9 miles. Each boat is approximately 44 miles from the lighthouse.
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