Find the area of the parallelogram with the given vertices: (0,0), (2,6), (11,8), (9,2).

Let

u = 2i+6j
v = 11i+8j
Then the area is
|u×v| = 50

or .... list the points in clockwise order, starting with any point, but repeating the starting point.

9 2
11 8
2 6
0 0
9 2

area = (1/2)(sum of downproducts - sum of up-products)
= (1/2)( 72+66+0+0 - (22+16+0+0))
= (1/2)(100) = 50