Answer:
D(-5, -5)
D(2, -2)
D(-1, -1)
D(2, 1)
Step-by-step explanation:
Plot each set of 3 points and figure out which vertex is missing.
A(-5, -1), B(1, -1), and C(1, -5)
Missing: D(-5, -5)
A(2, 3), B(7, 3), and C(7, -2)
Missing: D(2, -2)
A(-1, 4), B(7, 4), and C(7, -1)
Missing: D(-1, -1)
A(2, 5), B(6, 5), and C(6, 1)
Missing: D(2, 1)