cannot select lines which i want to mirror in mirror command

[shivamagarwal2112]

I sketch the half of my drawing, when I click on mirror and try to select line it does nothing but asks me to select objects.
when i click on the lines it does nothing

[etfrench · Accepted solution]

In the Mirror dialog, you have Faces selected, which means you're trying to mirror sketch items with the 3d model Mirror command.  Select the Mirror command from the Sketch menu and it will work fine.

[lichtzeichenanlage]

Like @etfrench said. But a better practice is to extrude the half body and than mirror this. Experienced users in this forum to prefer this, because sketches will slow down easily. 

[shivamagarwal2112]

@lichtzeichenanlage can you explain plz , im a bit of a rookie.

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[lichtzeichenanlage]

@shivamagarwal2112: Sry for my late reply but on one side I had lost myself in another project on the other side the weather here in Germany was just to nice (even 28°C in the north of Germany). 

Fusion 360 slows down easily if sketches are getting complicated. Keep them simple is a good rule of thumb. And this means that you e.g. should avoid mirroring or patterning in sketches. Just do it with features. But this is again just a rule of thumb.

This example shows, that the sketch freezes for some time because of the pattern feature but doing the same thing with a feature based pattern works out well.

Other things you might want to learn is constraining your sketches and the Rule #1.