The difference in the 2 consumer surpluses is where the bottom right corner of the triangle is and then you just calculate the area for the area respectively:

The one where its regulated is at [70,7] or where AC and demand meet. This is also the farthest the company can go without sustaining a loss. (.5x70x7)

But if its at the profit maximization point then the bottom right corner is at [50,9] this is where the company is the most profitable or where MR=MC and then just continue up to the demand curve and that's where the bottom corner is (.5x50x5)