gamma is the angle subtended by the arc. Area of a sector is 1/2 gamma r^2 and radius is just 1. Should the area of the sector be 1/2 gamma?

Hmmm. I think you are right. Great catch!

gamma is the angle subtended by the arc. Area of a sector is 1/2 gamma r^2 and radius is just 1. Should the area of the sector be 1/2 gamma?

Hmmm. I think you are right. Great catch!