We know that the sum of the angles in a triangle is $180^{\circ}$. So, we subtract the sum of the given angles from $180^{\circ}$ to find angle $B$.
\[B = 180^{\circ} - (27.2^{\circ} + 115.5^{\circ}) = 180^{\circ} - 142.7^{\circ} = 37.3^{\circ}\]
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