Jack's Blocks
Free Quilt Block Pattern
The Jack's Blocks quilt block was new to me. I have no idea who "Jack" might be, but this does make an interesting five patch design.
The quilt block is an easy one to construct but you need to take careful note of the symmetry of the block in the placement of the patches. As long as your half square triangles are pointing in the correct direction, this block will go together in no time.