Kelly wants to enclose a rectangular area for her dog with 240 feet of fencing. she wants the width to be 20 feet. what will be the length of the rectangular area

Fencing means perimeter so that mean 2 times the length + 2 times the width.
Kelly has 240 feet of fencing and the width is 20 feet. So 240 = 2 lengths + 2 widths. So we have to multiply the width by 2 and subtract it from 240. 20x2 = 40. Now 240-40 = 200. So we are left with 200 feet of fencing for the length. Since we have to multiply the length by 2 in the perimeter, we can divide 200 by 2 to get the length. 200/2 = 100. So the length of the fence is 100 feet. Hope this helps and if so please leave a good rating and thanks and maybe even brainliest answer. Thank you I really appreciate it. Have a nice day!