If ad = 6 and BD = 5, the sum of areas of △ ADF and △ BDE can be obtained

If ad = 6 and BD = 5, the sum of areas of △ ADF and △ BDE can be obtained

The length of DF, AF, be is calculated. The area of △ ADF is 540 / 61, the area of △ BDE is 375 / 61, and the area sum of △ ADF and △ BDE is 15