Thinking of making bass traps - will these dimensions work-150 x 350 x 1600 mm?

I've decided I have to put up some bass traps in the 4 corners of my room.  But due to the layout and more importantly the WAF factor, I am limited to what I can build.  I'm wanting to build 4 (one for each corner), with dimensions 350-400mm wide, 150 thick (3 x 50mm rigid fibreglass boards glued back to back), and about 1600mm high.  Essentially it will be 3 layers of 50mm uthermo rigid fibreglass glued to each other.  Will this work, or are the dimensions too small?  Unfortunately, I don't have the space for anything much bigger. 

I'm thinking of mounting them 50mm off the corners of the walls, and about 100mm off the floor

Any advice is appreciated.  Plus advice as to how to make them and assemble them.  Even direct me to forum posts that will help, please