Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 5 - No. 19)
If the angle of depression from a point A to a point B is 30°, what is the angle of elevation from point B to point A?
30°
60°
120°
150°
คำอธิบาย
The angle of elevation is the same as the angle of depression.