Find the perimeter of a rectangle with a length of $20$20 m and a width of $7$7 m.
Find the perimeter of a rectangle with a length of $2$2 m, and a width of $13$13 m.
Find the perimeter of a scalene triangle with side lengths $13$13 mm, $17$17 mm and $18$18 mm.
Find the perimeter of an equilateral triangle with a side length of $4$4 m.