How to make polygons shift base angle?

[gumbo23]

I want to make an octagon. When I make a polygon and set the number of sides to eight, it makes the points the top and bottom, rather than the base.

I want to convert it to a text frame, so that text sits in the base of the octagon. So how do I make a flat surface the base? If I use the rotate feature, it still forces the text to run at an angle.

Thanks.

[G13RL]

Turn the octagon by 22.5°.
Copy the octagon for later use.

Draw behind the octagon a square bigger than it, select the set and do "Intersect".
Transform the result to "Text Frame" and type the text ("Justify Center" and "Bottom Align"), set "Baseline" if necessary.
Paste the previously copied octagon and place it under the text.

[gumbo23]

Thanks. I was really hoping it was way simpler than this. 

If anyone has an easier way to do this, please share.

[Alfred]

1 hour ago, G13RL said:

Draw behind the octagon a square bigger than it, select the set and do "Intersect"

Marginally quicker: with the octagon selected, do a Boolean ‘Add’. The original octagon will be added to itself, obviating the need to create an extra object.

[G13RL]

Thank you @Alfred, it is indeed simpler and faster!

[gumbo23]

13 hours ago, Alfred said:

Marginally quicker: with the octagon selected, do a Boolean ‘Add’. The original octagon will be added to itself, obviating the need to create an extra object.

How do you do a Boolean add?

[GarryP]

Try menu “Layer → Geometry → Add”, or use the button which might be on your Toolbar, as in the attached image.