The area of the quadrangle is calculated using the formula of the sum of the length of the four sides and the diagonal.

Enter the length of four side(a, b, c, and d) and sum of the diagonal(A+B), and click "Calculate area of quadrangle", the area of the quadrangle is calculated from the length of four side and the sum of the diagonal, and it is displayed.

### The area of quadrangle whose the base a is 3, the base b is 4, the base c is 5, the base d is 6, and the sum of the diagonal(A+B) is 180.

Area S: 18.97366596101