Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 5 - No. 21)
If the angle of elevation of the top of a tower from point A is 30°, and the distance from A to the base of the tower is 20 meters, what is the height of the tower?
10 m
20√3/3 m
20 m
40 m
คำอธิบาย
tan(30°) = h/20; h = 20 * tan(30°) = 20 * (1/√3) = 20√3/3