I do not understand why I can´t offset this sketch curves

[lhelle]

Sorry if it is a basic question but I just don't know what is missing here. The blue shape it is a simple set of straight lines and two arcs and it just wont offset, I checked the curves to be on the same plane, even deleted all constraints to check but i just don´t let me select the arcs when I try to offset. 
Any help would be greatly appreciated.
Thanks in advance.

[davebYYPCU]

Sketch > ... > Offset works when editing the sketch the curves belong to.

Double click an article and Fusion will select the chain of articles that are coincident connected.

You cannot Offset a chain of Offset curves, but the original set of articles can be Offset many times.

Might help...

[lhelle]

Thank you for your quick response, does this mean that for me to offset this curve I would need to reconsctruct the shape every time I derive the curves from another sketch/3d Shape?

[davebYYPCU]

No, 

Edit sketch, Start the Offset Tool, select the articles you want to copy set the distance to offset.

Text box will take positive or negative numbers for the other side, 

Might help....

[lhelle]

Thank you, I understand how to use the offset tool, but I'm having trouble with this particular set of curves, I can't select all curves to make one continuos offset line

[davebYYPCU]

Double click an article and Fusion will select the chain of articles that are coincident connected.

If the articles are not joined (zoom right in) they will not chain select.

Might help....

[lhelle]

Thank you for all your answers, I double checked the curve, there is a constraint for coincident endpoints between the arc and the straight line and when I double click the selection ends in that point, I tried redrawing the curve and it doesn't work. 

Sorry if this comes as a noob question but it doesn't make sense.

[jeff_strater]

please share your design here.  We can take a look at it