Explanation:
we will assume that all the angles of the chicken enclosure are 90°, right angles.
then the long left side must be 5 + 6 = 11 m.
and the short bottom side must be 12 - 8 = 4 m.
so, the perimeter (the whole way around it) of the chicken enclosure is
12 + 5 + 8 + 6 + 4 + 11 = 46 m
each meter of fence costs £7.99.
so, the total costs are
46 × 7.99 = £367.54