Best clamping method plz help

I have a traingular shelf so it's a triangular frame with two shelves within it I am using two strap clamps which meet the corners nicely but I don't know how to clamp the two middle shelves, I have tried placing a block one side the same angle as the frame and other side square for the clamps but when I try to tighten them the blocks just slide towards the top. There are two things that come to mind

a:) using a glue gun to fix the blocks
b:) using double sides tape

But I am worried that both will be hard to get off especially the tape.

Any ideas anyone.

Cut two triangular pieces and place them next to your frame. Clamp in both vertical and horizontal directions and your shelves should be secure

How does it help by using a triangular piece and placing a clamp vertically. The angle of one side of the frame is 27.5 two angles equal 125°, I'm not sure what you mean.:?

Attachment 321683
Does this picture make sense? Apply the clamping pressure evenly and clamp from both the "vertical" and "horizontal" directions.

I had a similar problem when clamping up a triangular shelf unit. I used blocks as described above and glued a strip of sandpaper on the side of the clamping block that was against the frame of the unit. That gripped on the unit to allow me to tighten the clamps across the unit without the blocks slipping.

Hope that makes sense and helps

Thanks guys both are excellent much better than what I came up with, I clamped two stop blocks to stop the other blocks from moving up. The triangle is by the best and should work like dream hopefully the only thing is I decided to texture it with a scrub plane so just maybe it won't have any grip but if I switch to the sand paper trick that will do it.

Thanks heaps fellas

I am surprised there wasn't a bigger response from more out there is everyone in hibernation. lol

thanks again:)