# Casey's Angle

## John Casey (1820-1891)

To celebrate the bicentenary of the birth of BOC = B'O'C'.
12 points are shown here, 7 large and 5 small. Move the seven large ones as you will to explore Casey's angle.
How can you accurately describe what you observe?
For more information about Casey, his work and, in particular, his angle, check out

**John Casey**on 12 May 1820, this applet illustrates**Casey's angle**,**Peter Lynch**'s*in the***That's Maths****of 7 May.***Irish Times***Pauline Romera-Lebret**situates Casey's work on 'new triangle geometry' in the context of teaching geometry in Europe and the USA in**, Reykjavik, 2009.***Dig where you stand*## New Resources

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