Synclastic

As synclastically one calls the same direction curvature of a dome ( Greek preposition syn: together, in common with). It has a positive degree of curvature

${\displaystyle \kappa ={\frac {1}{\mathrm {r} 1*r2}}>0}$,

because the two main radii of curvature r1 and r2 are on the same side. In contrast, an anticlastic bowl is curved in opposite directions and has a negative degree of curvature.

Domes and shells belong to the planar structures and have a three-dimensional load - bearing behavior, as there is a third direction due to the curvature . Slabs and panes, on the other hand, are flat 2D structures.