WAEC Mathematics 2023 Paper

Concept:Use the tangent ratio for the right-angled triangle formed by the horizontal distance and the vertical height difference between the eye and the top of the building.Explanation:Height of the building $= 58\ \mathrm{m}$Height of Mrs Kebeh's eye $= 2\ \mathrm{m}$Vertical height from her eye to the top $= 58 - 2 = 56\ \mathrm{m}$Horizontal distance from the building $= 110\ \mathrm{m}$$\tan \theta = \frac{\text{opposite}}{\text{adjacent}} = \frac{56}{110}$$\frac{56}{110} = 0.5091$$\theta = \tan^{-1}(0.5091)$$\theta \approx 27^\circ$ (to the nearest degree)Answer:The angle of elevation is $27^{\circ}$, which is option A.