Are parietal bones paired?

The parietal bone is a flat bone because it is located in your skull

There are multiple unpaired bones of the skull. The unpaired cranial bones are the frontal, occipital, sphenoid, and ethmoid bones. The unpaired facial bones are the vomer, mandible, and the hyoid.

Both. Based on shape it's irregular; however, it's also flat (unlike tubular bones).

The unpaired cranial bones include the frontal bone, occipital bone, sphenoid bone, and ethmoid bone. The unpaired facial bones include the vomer, mandible, and hyoid.sphenoid or the ethmoid

the sagittal suture