Hello xwrathbringerx1(a) Let . Then .

So (= total length of wire)

And

Then use

2(a) Draw vertical lines through the top vertices of the trapezium to the base. Then using the right-angled triangles thus formed, the width of the channel across the top is , and the depth of the channel .

Then use the formula:

Area of a trapezium = (sum of parallel sides) (perpendicular distance between them)

Grandad