Explanation:
From the data given:
tan5 = 131 / d₁
d, is the distance for points A
d₂ = 131/tan21 = 341.26ft
d₂ is the distance for points B
Distance from A to B
1497.3368 - 341.26666 = 1,156.1 ft
Thus, the distance from point A to point B is 1,156.1 ft if A boat is heading towards a lighthouse, whose beacon light is 142 feet above the water.