Those look like sketch geometry. If you're sure that they aren't useful, edit the sketch(es) in which they reside, select and delete. The easiest way to find the sketch is simply to select the element, then right click on it and choose Edit Sketch, or click the edit sketch icon in the mini-toolbar.
If, on the other hand, these are somehow important to the model function, then all you need to do is turn off visibility of the sketch.
Sam B
Inventor 2012 Certified Professional
Please click "Accept as Solution" if this response answers your question.
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Inventor Professional 2013 SP1.1 Update 1
Windows XP Pro 32-bit, SP3
HP EliteBook 8730w; 4 GB RAM; Core™ 2 Duo T9400 2.53 GHz; Quadro FX2700M
SpaceExplorer/SpaceNavigator NB, driver 3.7.18
still waiting for a foreshortened radius dimensioning tool in Drawing Manager