Geometry app warnings

[Alberto Candel]

In the Geometry Symbolic View I type

GA:=point(4, 3+e^(2*pi*i/5),3+e^(4*pi*i/5),3+e^(6*pi*i/5),3+e^(8*pi*i/5))
GB:=convexhull(GA)

then hit the Plot key and obtain a sequence of warnings like

Warning! Algebraic extension not implemented yet for poly[-1,0,30,-40,-5]

The numbers in brackets change.

Sometimes it stops and displays GB, which is a regular pentagon.

I cannot find an explanation for that warning in the User Guide. Any help? Thank you.

A.