We all have a six pack.  You have one right now.  Whether or not you can see that muscle (which in everyone’s body is shaped like a six pack—actually it looks like an eight pack) is determined by what you have on top of that muscle.  The skinniest person, even if they don’t have strong abs will have a six pack.  A heavier person with strong abs will also have a six pack, you just might not be able to see it.
So with that rationale I can guarantee you that you have a six-pack too.
Though we all want to see ours, it’s not the only abdominal muscle that is important.  We have two oblique muscles on each side and a deeper muscle (transverse) that lies underneath all our other ab muscles and works as a gentle corset to protect our spine and internal organs.  Learn to engage your transverse and you will have developed real ab strength.  Work to strengthen your rectus (or six pack muscle) and you might just wind up with bad posture. 
The obliques are large and can do more than the six-pack muscle.  Learn to use your obliques properly and you can get real control and tone over your abdomen.   When you use only your six pack muscle to curl yourself off the floor in abwork you create a bulge shape in your abdomen.  Use your obliques and your six-pack muscle together and only will you be able to have more strength and control but you’ll also build a flatter stomach.  Here’s to obliques helping you get a better six pack!