In △ ABC, if B = 5, ∠ B = π 4, Tana = 2, then Sina = 1___ ;a= ___ .

In △ ABC, if B = 5, ∠ B = π 4, Tana = 2, then Sina = 1___ ;a= ___ .

From Tana = 2, we get cos2a = 11 + tan2a = 15, from a ∈ (0, π), we get Sina = 1-15 = 255, according to the sine theorem, we get: Asina = bsinb, we get a = bsinasinb = 5 × 25522 = 210