That's a rectangle oriented along the axes.
AB=2 - -6 = 8
BC = 1 - -3 = 4
CD = 2 - -6 = 8
AD = 1 - -3 = 4
Area is 8×4=32
Answer: 32
----
The Shoelace Formula tells us the signed area of any polygon given the 2D vertices in order. It's half the sum of the cross product of the sides. If successive vertices are (a,b),(c,d) the cross product is ad-bc.
A(-6,-3) ,B (2,-3), C (2,1) , D (-6,1)
area = (1/2) ( (-6)(-3) - (-3)(2) + (2)(1) - (-3)(2) + 2(1) - 1(-6) + (-6)(-3) - (1)(-6)) = 32
