| 2026-05-06 | They're found in a circle |
| 2025-12-25 | Sides of pie slices, essentially |
| 2025-09-29 | Diameters halved |
| 2025-08-02 | They're all equal in a circle |
| 2025-06-15 | Pie chart dividers |
| 2024-07-15 | Diameter halves |
| 2024-01-31 | Arm bones |
| 2023-01-30 | Half-diameters |
| 2022-09-01 | Bicycle spokes, e.g. |
| 2022-03-30 | Minute hands, essentially |
| 2022-02-28 | Bones next to ulnae |
| 2021-09-19 | Straight sides of sectors |
| 2021-04-28 | Spokes, say |
| 2021-01-17 | Variables in (pi)r^2 and 2(pi)r |
| 2020-07-27 | Half-diameters |
| 2020-04-24 | Sides of Pac-Man's mouth, essentially |
| 2018-11-16 | Windmill blades, essentially |
| 2018-07-18 | r's, in geometry |
| 2018-02-07 | Ulnae neighbors |
| 2017-04-20 | Pie chart features |
| 2017-02-08 | Pie chart lines |
| 2016-09-07 | Circle lines |
| 2016-03-06 | Sides of sectors |
| 2015-06-08 | Half-diameters |
| 2014-10-25 | Minute hands, in a way |
| 2014-08-26 | Many lines on pie charts |
| 2014-06-01 | The two sides of Pac-Man's mouth, say |
| 2014-02-28 | Cuts into a pizza, often |
| 2013-11-17 | They come from the center |
| 2013-11-13 | Pizza cuts, essentially |
| 2013-05-12 | Arm bones |
| 2013-01-24 | Forearm bones |
| 2012-08-14 | Lines going out in all directions |
| 2012-08-08 | Spokes |
| 2010-10-20 | Circle measures |
| 2009-11-04 | Straight edges of pizza slices, essentially |
| 2009-01-11 | Parts of forearms |
| 2008-12-18 | They start in the middle |
| 2008-11-30 | r's, in math |
| 2008-06-26 | Circle lines |
| 2008-03-01 | Cuts into a pie, often |
| 2007-10-10 | Spokes, essentially |
| 2007-09-09 | Hub-to-rim lines |
| 2006-12-05 | Forearm bones |
| 2006-09-10 | They meet in the middle |
| 2006-08-31 | Projections from a central point |
| 2006-02-25 | Pie chart dividers |
| 2005-11-25 | They have a central meeting place |
| 2005-10-05 | State-named avenues in Washington, essentially |
| 2004-09-28 | Pie chart lines |
| 2004-08-17 | Arm bones |
| 2004-07-05 | Hub projections |
| 2004-05-18 | Spokes, e.g. |
| 2003-08-15 | Geometry calculations |
| 2003-08-12 | Diameter halves |
| 2002-03-16 | Angle producers |
| 2001-12-21 | Spokes |
| 2001-08-16 | Arm bones |
| 2000-11-02 | They meet in the middle |
| 2000-09-04 | Arm bones |
| 2000-08-18 | Rays |
| 2000-07-30 | Sector sides |
| 2000-07-04 | r's, in geometry |
| 2000-05-21 | Pie cuts, essentially |
| 2000-01-24 | Forearm bones |
| 1999-04-22 | Arm bones |
| 1999-03-21 | Lines on sonar screens |
| 1998-12-30 | Spokes |
| 1998-09-13 | Semidiameters |
| 1998-08-27 | Spoke more than once? |
| 1998-04-22 | They form central angles |
| 1998-02-10 | Wheel spokes, e.g. |
| 1997-10-25 | Minute hands, essentially |
| 1997-08-10 | Math measurements |
| 1996-12-14 | Pie cuts, essentially |
| 1996-06-15 | Spokes |
| 1996-03-06 | Spokes |
| 1995-07-21 | Diameters halved |
| 1994-11-30 | Arms of a sort |
| 1994-01-07 | Spokes |