Math Help - Geometry help

Hi I need help with a birdcage design.
i have to fit 20 birds in a birdcage and each bird takes up 0.1m cubed of space.
I have to find the dimensions and volumes of the birdcage.
the roof is 22 degrees and overhangs the frame by 200mm made of steel.
the concrete slab is 100mm.
quantities of material needed cement,sand,gravel for concrete.
the frame is made of timber and ther is a small door.the walls need to be covered by wire mesh.
quantities of wire mesh,timber, roof steel and door materials.
How do you make concrete.
How do i start this?
how to find the volume and suface area of this cagw?