Let BC = 2x and AC = 2y. Then MC = x and NC = y. Area(BCA) = (1/2) * BC * AC = (1/2) * 2x * 2y = 2xy. Area(MCN) = (1/2) * MC * NC = (1/2) * x * y = (1/2)xy. Area(BCA) / Area(MCN) = 2xy / ((1/2)xy) = 4. The area of triangle BCA is 4 times greater than the area of triangle MCN.