For a composite coil with straight and arc sections:
- Straight sections passing through the centre contribute zero magnetic field.
- Only the curved (arc) sections contribute.

For each arc of radius $r$ subtending angle $\phi$ at centre:
$$B_{arc} = \frac{\mu_0 I \phi}{4\pi r}$$

Net field = vector sum of fields from all arc sections (directions by right-hand rule).
(Exact numerical answer requires specific radii and angles from the figure.)