WAEC - Mathematics (1998 - No. 8)
When an aeroplane is 800m above the ground, its angle of elevation from a point P on the ground is 30o. How far is the plane from P by line of sight?
400m
800m
1500m
1600m
1700m
คำอธิบาย
From the diagram, \(\sin 30 = \frac{800}{x}\)
\(x = \frac{800}{\sin 30} \)
= \(\frac{800}{0.5} \)
= 1600 m