9514 1404 393
 5.3
Step-by-step explanation:
The formula for the area of a triangle is ...
 A = 1/2bh . . . . where b is the base length and h is the height.
The figure gives an area and shows b=h, so we have ...
 14 ft² = 1/2(h)(h)
 28 ft² = h² . . . . . . . . . multiply by 2
 h = √28 ft ≈ 5.3 ft . . . . . take the square root