Making an achway using Bend

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There are many ways of making an archway in wings - this is just another, but using one of the Vert | Bend commands.
1) Make a basic object that will form the archway (a semi-circular 'arch' with 2 vertical 'columns') - this will be referred to as a 'rod' when using the Bend tool.
I created the object shown in the following manner:
Create Cube
Scale X > 1000% (hold shift to constrain to 100% steps whilst dragging)
Edge > Cut > 3 (on all 4 long edges), followed by Edge | Connect to form 3 equal sections.
Edge > Cut > 8 on the 4 central section edges, followed by Edge > Connect.
Select all verticies

The 8 sections in the middle will form the semicircular arch and the the 2 outer sections the 'columns'.

2) Apply Vert | Clamped Plastic Bend - LMB option - and make sure you follow the info on the main info line.
For Rod centre - select the middle vert as shown (note all pix are views looking upwards on the underside of the 'rod' )

3) Rod Top - select the vert shown (the last section of what will be the semi-circular section.)
4) Bend Normal - choose any face on the underside of the 'rod' as this will give a normal (vector) pointing directly down (as shown) This vector will pass thro' the Rod Centre and also the centre of the bend - ie centre of the semicircle.

5) Top Clamp Point - select the vert shown (this is at the 'boundary' between the sections that will be 'bent' and those that remain straight.)

6) Bottom Clamp Point - select the vert shown (at the other 'boundary' point - on what will be the other side of the arch) and execute op - drag to 90deg (hold shift for 15deg 'steps') - 90 deg is the angle between Rod Top and Rod Centre positions.

7) Finished object / archway.

Experiment with different (Nos of) middle sections and different places for the various parameters - the positions chosen will give the greatest arch diameter (for this particular Bend option)
Note that I've not mentioned the full 'select / continue' sequence for specifying the various parameter like Rod Top / Bend Normal etc. - use the LMB select + RMB continue route if you're not comfortable with using the RMB select / continue method.