Question

Given the quadrilateral ABCD with the following vertices A(-4, 0), B(10, 0), C(10, 10), and D(0, 14), find its area.

Answer 1

After you sketch it, it is easy to see that you can split the area up into 2 triangle and a square, whose areas are 28, 20 and 100 , for a total of 148

or

list the coordinates in a column, repeating the first point

-4 0
10 0
10 10
0 14
-4 0

the area is (1/2)( sum of downproducts - sum of upproducts)
- (1/2)(0+100+140+0 -(0+0+0-56)
= (1/2(240 + 56) = 148