Answer: 12
Explanation:
You can find the area of a rectangle that forms around it, and then subtract the little extra triangles. You can form a 5 by 5 square around the points. There are 4 extra little triangles. Two of them have a base and height of 2 and 2. Two of them have a base and height of 3 and 3. So you get the total area of those 4 triangles to be: 2+2+4.5+4.5=13. So 25-13=12.