In a parallelogram ABCD with an area of 15, if AB = 5, BC = 6, then CE + CF=

In a parallelogram ABCD with an area of 15, if AB = 5, BC = 6, then CE + CF=

The area is known to be 15, and the length of both sides is also known. We can get the height AE = 5 / 3 AF = 3. Using right triangle, we can get DF = 3 radical 3 be = 5 / 2 radical 3. Then CE + CF = AB + bc-be-df result. I can't get the mathematical symbol