3. mr. frame builds windows. he uses the function p = 2l + 2w to determine the perimeter of a rectangular-shaped window with length l units and width w units. (a) write the function, using function notation, that mr. frame can use to find the perimeter of any window with a length of 5 ft, given the width. (b) write the function, using function notation, that mr. frame can use to find the perimeter of any window with a width of 3 ft, given the length.