Answer:
19 ft
Explanation:
Apparently, we are to assume the figure is a kite and that the diagonals cross at right angles. The area of such a figure is ...
A = (1/2)(d1)(d2)
Filling in the numbers, we get ...
114 ft^2 = (1/2)(d1)(12 ft)
d1 = (114 ft^2)/(6 ft) . . . . divide by the coefficient of d1
d1 = 19 ft