Triangles have long been popular in design, from Alexander Calder's mobiles to Konstantin Grcic's Chair One. They seem especially popular lately and we’ve noticed them everywhere from sheets to napkins.

Simple, modern, and sleek, we think they’re a fresh counterpoint to the stripes and nature-inspired patterns of the past few seasons.

1. Sit poolside in a triangle-adorned nook at the Kelly Wearstler-designed Avalon Hotel.
2. Sea-colored triangles bedeck Dwell Studio’s Mosaic line, $13-$77 (was $28-$160).
3. Bold triangles decorate one side of the Pink Bird pillow at Vitrine, $65.
4. Jonathan Adler’s sunny retro-style Oslo napkins, $12 each.
5. Mountains are reflected as pastel triangles in a Jamie Mills print from the Urban Outfitters/Society6 collaboration, $25-$55 depending on size.
6. Red triangles march cheerily across these Arrowhead sheets from Anthropologie, $170 (was $328).
7. Large-scale triangles energize Emma Gardner’s Pinwheels rug, starting at $2250.
8. Minimalist, metallic triangles on a throw pillow from Be Still, $50.
9. Washi tape-and-ink triangles on the Breakneck Vibes print from Neon and Neutral, $8.
10. The sleek Icon light by Moooi, available in the US this fall from Hive Modern.