I cut and pasted this directly from the scripting API, these are ALL of the arcs, there are no others available.
k0_360_Arc,
k0_60_Arc,
k60_120_Arc,
k120_180_Arc,
k180_240_Arc,
k240_300_Arc,
k300_360_Arc,
k30_90_Arc,
k90_150_Arc,
k150_210_Arc,
k210_270_Arc,
k270_330_Arc,
k330_30_Arc,
k345_15_Arc,
k165_195_Arc,