The formula below is called the semi perimeter of a triangle, where a, b, and c are the lengths of the three sides of the triangle. s= 1/2 (a+b+c) Solve this formula for c and please show your work no links

The length of a rectangular board is 3 feet less than twice its width. a second rectangular board is such that each of its dimensions is the reciprocal of the corresponding dimensions of the first rectangular board. if the perimeter of the second board is one-fifth the perimeter of the first, what is the perimeter of the first rectangular board?