help if you want to with area

A farmer grows crops on a square field, 400 metres on a side. He has divided this field into seven different sections, such that each section has the same area, and each section meets at a point in the exact center of the field.

http://www.geocities.com/lookalikeroofio/untitled.GIF

If he wants to build a fence along the perimeter of the two sections (the perimeter outlined in red), how many metres of fence is required? Round up to the nearest whole number, and please only submit a number as your answer