What is the magnetic field at O due to current in the B infinite wire forming a loop as shown in fig. ?

Here required angles θ1 and θ2 are 90∘−ϕ1 and 90∘−ϕ2 HenceB =μ0i4πdsin⁡90∘−ϕ1+sin⁡90∘−ϕ2=μ0I˙4πdcos⁡ϕ1+cos⁡ϕ2