C-09-Q120mediumsingle_mcqsin30∘=?\sin 30^\circ = ?sin30∘=?a12\dfrac{1}{2}21b12\dfrac{1}{\sqrt{2}}21c32\dfrac{\sqrt{3}}{2}23d111ব্যাখ্যাsin30∘\sin30^\circsin30∘ is the ratio of the opposite side to the hypotenuse, PMOP=a2a=12\dfrac{PM}{OP}=\dfrac{a}{2a}=\dfrac12OPPM=2aa=21. This is a standard value.