△ABC has verticles A(1,1), B(1,7), and C(6,5).

What is the area of △ABC?
A. 12 units
B. 15 units
C. 20 units
D. 14 units

2 answers

If you let AB be the base, then it is easy to see that the altitude is 5.
1/2 (6)(5) = 15
A = 1/2(h*b) = 1/2(7-1)(6-1) = 15 units.