Answer:
20
Explanation:
To find area using coordinates, you would take the y-value of the first coordinate and the x-value of the second coordinate and multiply them. Then, take the x-value of the first coordinate and multiply it with the second y-coordinate. Take the second number and subtract it from the first number. for multiple coordinates, you would multiply the first and the second, the second and the third, and so on. Once you reach the last coordinate, just multiply it by the first again. then, take all of the numbers, from multiplying your coordinates and add them together and divide them by 2 to find your area.
We would start with coordinate (8,1) here because it's letter variable is W, which is first of the others alphabetically.
(8,1) (1,1)
1 x 1 = 1
8 x 1 = 8
1 - 8 = -7
next coordinate:
(1,1) (2,5)
1 x 2 = 2
1 x 5 = 5
2 - 5 = -3
next:
(2,5) (5,5)
5 x 5 = 25
2 x 5 = 10
25 - 10 = 15
next:
(5,5) (8,1)
5 x 5 = 40
5 x 1 = 5
40 - 5 = 35
-7 - 3 + 15 + 35 = 40
40/2 = 20