How cut circle/diamond shape exactly in middle?

[MxHeppa]

How cut circle/diamond shape exactly in middle? or any other shapes sameway. i found making circle using two pie pieces shape is not exactly same. same with triangles but for diamond shape.

[GarryP]

For a diamond it depends on your ‘line of symmetry’.
If you want to get a 'half-diamond' shape down the vertical/horizontal ‘axis’ (from vertex to opposite vertex) then you could just draw a triangle.
For another way to ‘half it’ see the advice below.

If you want to create a ‘half-circle’ then you can use the Segment Tool.

If you already have your shape then one easy way to ‘half it’ is to create a rectangle which covers exactly half of the existing shape and subtract the rectangle.

If none of this helps then we will probably need more information about exactly what you have and exactly what you want to do with it – explanatory images are usually useful.