Prism Volume = Area of Base • Height
Area of Base = Prism Volume / Height
Area of Base = 840 / 14
Area of Base = 60
pentagon area = 5 * side^2 / 4 * tan (180 / 5)
side^2 = [pentagon area * 4 * tan (180 / 5)] / 5
side^2 = [60 * 4 * tan (36)] / 5
side^2 =240 * 0.72654 / 5
side^2 = 174.3696 / 5
side^2 = 34.87392
side = 5.9054144647
Pentagon Perimeter = 5.9054144647* 5
Pentagon Perimeter = 29.5270723235