This is the concept of geometry, the length of the lateral edge of the prism will be given by: Length=[lateral area]/[area of the hexagon] lateral area=360cm^2 area of hexagon will be: Area=a^2ntan(180/n) where; n=number of sides a=apothem size A=5^2*6tan(180/6) A=86.60 Thus the length will be: length=360/86.6 =4.2 cm