The answer is 4 feet. Draw a line segment from D perpendicular to AC and intersect AC at F. triangle ADF is a right triangle, with angle AFD=90, Angle DAF=half of BAC=30 in a 30-60-90 triangle, the shortest side is half of the hypotenuse. the hypotenuse AD=8, so DF=4 Draw a line segment perpendicular from D to AB and intercept AB at E. DE is also 4 feet, same as above.