Need to make your own equations the. Solve it not sure how pretty sure you use a derrivitive then use restrictions from the question please help

1. Four pens, one square and three rectangular, are to be built using 300 m of fencing. The layout of the pens is shown below. Determine the dimensions that maximize the total enclosed area. Assume, for practical purposes, that the sides marked with | | must be at least 18 m in length, while those marked with | must be at least 22 m in length. atm [T/C 9] K > 1 18 m 3 ( Dry ) + 2 ( C ) = 300m X 3 x. 3y +20 = 300m 3x . 34 300- 250 6 + Tac = 300