Math Homework about Trigonometry - Sine Rule.

On a map whose scale is 8 cm to 1 km, an estate is shown as a quadrilateral ABCD. The length of the diagonal AC is 7 cm, BÂC = 55°, BĈA = 77°, DÂC = 90° and DĈA = 40°. (DRAW THE FIGURE)
Calculate:
a) the length, in cm, of the side AB on the map;
b) the length, in km, which represented by AD;
c) the area, in km², which represented by ΔADC.