细胞分裂使细胞数目增多，细胞生长使细胞体积增大，而细胞分化可以形成不同的组织．对此，以下描述正确的是（　　）

China is very famous(著名的) for its food in the world. There are many kinds of food in China. They're Cantonese(广东的) food, Sichuan food, Shanghai food, Hunan food and so on. And I like Sichuan food best.
Now, Sichuan food is very popular. There are many Sichuan food restaurants all over the country. Sichuan food is very hot(辣的), but people love it. In some famous Sichuan food restaurants, you can see many people waiting there. Now in Beijing, there are more and more Sichuan food restaurants.

如图所示，某住宅小区有一个矩形休闲广场ABCD，其中AB=40 米，BC=30 米，根据小区业主建议，需将其扩大成矩形区域EFGH，要求A、B、C、D四个点分别在矩形EFGH的四条边（不含顶点）上．设∠BAE=θ，EF长为y米．

（1）将y表示成θ的函数；

（2）求矩形区域EFGH的面积的最大值．