# What is length in integrate variables of a sliced surface
**URL:** https://discourse.paraview.org/t/what-is-length-in-integrate-variables-of-a-sliced-surface/9742
**Category:** ParaView Support
**Created:** [June 6, 2022, 7:57am UTC](https://discourse.paraview.org/t/what-is-length-in-integrate-variables-of-a-sliced-surface/9742 "2022-06-06T07:57:06Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Bushra](https://discourse.paraview.org/u/Bushra)
#### Post date: [June 6, 2022, 7:57am UTC](https://discourse.paraview.org/t/what-is-length-in-integrate-variables-of-a-sliced-surface/9742/1 "2022-06-06T07:57:06Z")
Hi!
I want to calculate perimeter of a 3D building with slice surface shown in picture attached
When I use integrate variables and view cell data in spreadsheet, it shows me length in one column. I want to know if this length is the total perimeter of three buildings? or is it something else? How do I calculate the covered area of building?
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### Author:  [@mau\_igna\_06](https://discourse.paraview.org/u/mau_igna_06)
#### Post date: [June 7, 2022, 7:02pm UTC](https://discourse.paraview.org/t/what-is-length-in-integrate-variables-of-a-sliced-surface/9742/2 "2022-06-07T19:02:52Z")
Supposing each building is a polyline you can use vtkTriangleFilter to create the faces and extrude them
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### Author:  [@mau\_igna\_06](https://discourse.paraview.org/u/mau_igna_06)
#### Post date: [June 8, 2022, 7:33pm UTC](https://discourse.paraview.org/t/what-is-length-in-integrate-variables-of-a-sliced-surface/9742/3 "2022-06-08T19:33:05Z")
Sorry. I didn’t read yior question carefully, without the extrusion you should be able to get the area with vtkMassProperties filter
About the perimer I think you should do vtkstripper with connect contiguous segments or vtkPolydata conectivity filter, I’m not sure anout the orther and after that you need to traverse all the points of a cell polyline summimg the distamce on poimt i with point i+1
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### Author:  [@Kenichiro-Yoshimi](https://discourse.paraview.org/u/Kenichiro-Yoshimi)
#### Post date: [June 9, 2022, 12:13am UTC](https://discourse.paraview.org/t/what-is-length-in-integrate-variables-of-a-sliced-surface/9742/4 "2022-06-09T00:13:12Z")
Hi,
For the perimeter of each section line, it may be easier to use the **Plot On Sorted Lines** filter. This filter puts the section line of each building into one block and calculates the **arc\_length** of each.
