In △ ABC, a = xcm, B = 2cm, B = 45 ° are known. If there are two solutions of triangle by using sine definite, then the value range of X is () A. 2<x<22B. 2<x≤22C. x>2D. x<2

In △ ABC, a = xcm, B = 2cm, B = 45 ° are known. If there are two solutions of triangle by using sine definite, then the value range of X is () A. 2<x<22B. 2<x≤22C. x>2D. x<2


∵ in △ ABC, a = xcm, B = 2cm, B = 45 °, according to the sine theorem Asina = bsinb, Sina = asinbb = x · 222 = 24x, ∵ B = 45 °, 0 < a < 135 °, in order to make the triangle have two solutions, we can get 45 ° < a < 135 °, that is 22 < Sina < 1, ∵ 22 < 24x < 1, the solution is 2 < x < 22, so we choose: a