Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 4 - No. 10)
If sinA = 0.6 and angle A is obtuse, what is the value of angle A?
36.87°
53.13°
126.87°
143.13°
คำอธิบาย
Use arcsin(0.6) = 36.87, then find the supplementary angle of 36.87° by subtracting it from 180° (180 - 36.87 = 143.13).