Draw a triangle. Easy, right? Now try drawing a balbis. That might sound much harder—until you realize that you’ve actually been doing it since Kindergarten (keep reading). There are a number of shapes most of us come into contact with every day while blissfully unaware of what to actually call them.

1. Balbis

The best-known example of this shape is the capital letter H. Mathematically, a “balbis” is defined as a single line that is terminated by a secondary line at each end, both of which are positioned at right angles to the primary line.

2. Squircle


Like the oft-ridiculed “spork,” this shape’s name betrays its identity: it’s essentially a circle/square hybrid with properties of both. Lately, squircles have found widespread use in modern car designs

3. Heptagram


A seven-pointed star which appears in the flags of Australia and the Cherokee Nation.

4. Triquetra

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Also known as a “trefoil knot," triquetras are a staple of Celtic and early Christian art (sometimes drawn interlaced with a circle).

5. Star of Lakshmi


Another shape of religious significance, the eight points of this star represent the eight types of wealth provided by the goddess Lakshmi.

6. Lemniscate


Two loops that meet at a central point form this shape, which has become the famous “infinity symbol.”

7. Vesica Piscis

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In America, when something’s called “football-shaped,” this is generally what the person is talking about. One can create a vesica piscis by overlapping two circles with equal radiuses so that the edge of each one touches the others’ center. In this image, the vesica piscis itself is the lightly-shaded area between the two “crescent-moon” shapes. 

8. Stadium

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Not to be confused with the sporting venue, a geometric “stadium” is a rectangle with a pair of semi-circles positioned at opposite ends.

9. Nonagon

A nine-sided polygon which inspired a catchy tune by They Might Be Giants. Temples of the Bahá'í faith are required to have a nonagonical outline.

10. Enneagram

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Also known as the “Star of Goliath,” this nine-pointed star has been adopted as the logo of the popular heavy metal band Slipknot.

11. Annulus

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The technical term for a “ring shape,” an annulus is formed in the space between two concentric circles. 

12. Reuleaux Triangle


Popularly used on guitar picks and trail route signs, this curvaceous triangle-like shape is named after German engineer Franz Reuleaux. For more details, skip to the 1:20-mark of this video from Numberphile: