Maths question please help

[Talkyo]

Can someone please help me and tell me if I had a 0.23m border within the edge of this whole area, what this would be in linear metres please?

Do you mean another line that is 0.23 m away from the outside line?
If so, it would be 27.49m in total - however where the bay window is, you’ve not put the measurements around the bay so in reality the whole perimeter would be slightly less.

Sorry, I’ve make a mistake but can’t edit it again! I’ll try again.
starting from the top side going clockwise
604 + 769 + 604 + 284* + 180 + 296 + 200 + 204 = 31.41m

Hi sorry it will be on the inside and the line on the plan will be the outer edge.

Like this -

That’s it