Chi can be good as well as bad. The negative Chi is generated by angles. It is called Sha Chi. Poisonous arrows or sharp angles centered around main door of the house or the road coming to main door of house form sha.
Sharp corners of the building surrounding your house shoot poisonous arrows towards any object coming in their path. These corners should not be visible to you. However if these are visible, corrections should be made so that these are not seen by you. For example, a pakua mirror may be hanged so that sha is rebounded back.
Feng Shui Has Remedy For Everything
If the sharp corner is not visible there is no need of worry, otherwise remedial measures are required.