[header] How to build and use a small greenhouse out of transparent corrugated sheet [title] Assemble the supplies needed. [step] Check the " things you'll need " list below. [title] Cut and bend 3 mm iron wire to form 2 bows. 
[step] Each bow has 5 loops as shown on the photo below. The distance between the two u shaped ends is about 1 cm (3/8 inch) larger than the width of the corrugated sheet used for the tunnel.