Find the areas of the three polygons described by the following conditions (a), (b) and (c), respectively.
(a) the system of inequalities |x| \leq 1 and |y| \leq 1
(b) the inequality |x|+|y| \leq 10
(c) the inequality |x|+|y|+|x+y| \leq 2020
Find the areas of the three polygons described by the following conditions (a), (b) and (c), respectively.
(a) the system of inequalities |x| \leq 1 and |y| \leq 1
(b) the inequality |x|+|y| \leq 10
(c) the inequality |x|+|y|+|x+y| \leq 2020