The area of the shaded quadrilateral is V . The area of the quadrilateral corresponds to the V between The blue line on the following graph shows a firm's daily costs for the first 90 days of the fiscal year. Because the firm is expanding, its costs are constantly rising. 10 CO EXPENSES (Thousands of dollars per day) 0 10 20 30 40 50 60 70 80 90 100 TIME (Days)