Answer:
area = 10
Explanation:
Triangle BOC is a right triangle. You can see this because the slope of BO and OC are negative reciprocals (opposite sign and flipped over) You can calculate the slope, m.
m = (y-Y)/(x-X)
Slope of BO is 4/2,
slope of OC is -2/4.
see image.
So then you can use BO and OC as the base and height in an area calculation.
But first you have to calculate the length of each. Luckily they are the same length. You can use distance formula, but when you have a picture, you can just see to use Pythagorean theorem (distance formula comes from PythagThm anyway)
Both BO and OC have legs length 2 and 4. See image. They are both length sqrt20.
Use Area= 1/2bh to find the area. See image.