It's mid-term season, so add some pi factor to your living space this fall. Circles, squares, curves and lines come together for some pattern play in these coffee and side tables. Compass and protractor not required.

STACK AND TILTThe Levels table ($5,865, pictured above) by Belgian design house Per/Use is like a big, beautiful jigsaw puzzle for the style set—move each piece into whatever shapely arrangement you’re in the mood for.COFFEETABLEWH_LIFE1_1 SIZE MATTERSSize—and shape—does count when it comes to coffee tables. Let your sofa be your scale guide, and match coffee table height to the sofa’s seat height. But forget this rule when it comes to length: a coffee table should be narrower than the sofa for a layering effect. And, while opposites do attract (think rustic juxtaposed with formal or modern counterbalanced with traditional), stick to similar shapes in furniture arrangements. A round table may not be the best choice with a long, rectangular sofa—you’ll leave anyone seated on the far edges clinging to their cocktails rather than stretching for a distant perch at the alienating table. Go elongated oval instead. Of course, you could also add within-reach side tables—a good excuse for some more shopping.Natuzzi Ocean_SideBIG WAVEThe Canaletto-walnut and matte-brown-lacquer Ocean table by Natuzzi ($1,869) evokes water’s ebb and flow.FOLD Ligne Roset 2CIRCULAR LOGICCompressing or stretching in size, the Fold table for Ligne Roset ($2,298) is designer Philippe Nigro’s take on the nesting table—a study in circular divinity.DRUMPC_OW3_1GRID WORKBend Goods manipulates hot-dip galvanized iron into a lattice-like network of shapes in pop-art colours. This Drum ($525) has a serious beat.BrooklynCubeNICE LINESAll angles and intersecting lines, this iron Brooklyn cube ($275) is part engineering elegance (think trestle and gridiron bridges) and part industrial chic, much like the borough it’s named for.