8. A farmer is building an enclosure for a vegetable patch next to an existing wall. What is the maximum possible area of the enclosure that she can build if available materials can be used to construct a total of 80 meters of fencing for the three walls to be built? 9. A farmer is building an enclosure in the shape of an equilateral triangle using part of an existing wall as a base of this triangle. What is the base and the height of the triangle that provides the maximum possible area if the total lengths of fencing available for the two sides is 48 meters?

10. A town T is located 6 km away from a rail line (this is the distance from T to the closest point A on the rail line). The distance from city C to point A is 24km along the rail line, which runs straight. A station S is to be built on the rail line to serve town T. Passengers will take LRT from C to S and then transfer to the bus along a straight road to be built from S to T. The speed of LRT is 1.2 km/min, and the speed of a bus is 1 km/min. What should be the distance from A to S, so that the total travel time from city C to town T is the shortest possible?