-1 points SPreCalc7 2 FoM 029. A graphing calculator is recommended. A rancher wants to build a rectangular pen with an area of 81 m2 (a) Find a function that models the length F of fencing required, in terms of the width w of the pen. F(w)- (b) Find the pen dimensions that require the minimum amount of fencing. width length Need Help?LReadN Submit Assignment Save Assignment Progress