Two ideas come to mind:

"lines of inquiry"

or (if the text is not particularly formal) a rephrase:

"...will focus on three areas: a, b, c"

"These areas are presented/outlined in chapter..."

I'd be slightly more inclined to go with "lines of inquiry", though.

e.g. "The team's work has contributed massively to the debate and opened up several *lines of inquiry* and a number of other laboratories around the world have also detected MAP in the bowels of Crohn's disease sufferers."
http://www.action.org.uk/news_media/crohns.php

"Memorandum submitted by the Academy of Medical Sciences...

The Academy would like to suggest the following *lines of inquiry*:—

GENERAL

(a) What are the numbers of applications for programme and project grants made to the MRC under its response mode mechanisms over the past five (or perhaps eight) years? ...

(b) Is the apparent loss of response mode funding the result of a deliberate policy towards in-house (unit and institute) funding? If so, what is the reasoning behind this policy and what is seen as the endpoint of these trends? ... etc.
http://www.publications.parliament.uk/pa/cm200203/cmselect/c...

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Note added at 4 hrs (2007-04-05 12:57:20 GMT)
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Another (possibly more relevant) example:

"The project will follow two major lines of enquiry in order to achieve the study objectives..."
http://www.cs.bris.ac.uk/Research/MachineLearning/hes.html

And I should add that I'd rather use something like "will follow/pursue/address" for "are" here, if they fit with the register, since "has" doesn't sound quite right to me here alongside this phrase.