Please help and show the steps

Which of the choices shown could be used to prove that aacp=abcp ?

Find the area of the regular hexagon if a side is 20 cm.

Marquise has 200 meters of fencing to build a rectangular garden. the garden's area (in square meters) as a function of the garden's width w w (in meters) is modeled by: a ( w ) = − w 2 + 1 0 0 w a(w)=−w 2 +100w what side width will produce the maximum garden area? meters