$${B = \sqrt{B_1^2 + B_2^2} = \frac{\mu_0}{2 \pi d (\cos 45^{\circ})} \sqrt{i_1^2 + i_2^2} \\ = \frac{(4 \pi \times 10^{-7}\, \mathrm{T \cdot m/A})\sqrt{(15\, \mathrm{A})^2 + (32\, \mathrm{A})^2}}{(2 \pi)(5,3 \times 10^{-2}\, \mathrm{m})(\cos 45^{\circ})} \\ = 1,89 \times 10^{-4}\, \mathrm{T} \approx \underline{\underline{190\, \mathrm{\mu T}}}}$$