You must show all formulas used and show your step-by-step calculations.
1. Create a quadrilateral on a coordinate grid. (It cannot be an irregular quadrilateral, so choose your coordinates accordingly). Draw iff

Step 1 ：\(\text{Let's choose the coordinates of the quadrilateral as follows:}\)

Step 2 ：\(A(0, 0), B(2, 0), C(2, 2), D(0, 2)\)

Step 3 ：\(\text{Divide the quadrilateral into two triangles:}\)

Step 4 ：\(\triangle ABC \text{ and } \triangle ADC\)

Step 5 ：\(\text{Since } AB \text{ is horizontal, the area of } \triangle ABC \text{ is:}\)

Step 6 ：\(\frac{1}{2} \cdot AB \cdot BC = \frac{1}{2} \cdot 2 \cdot 2 = 2\)

Step 7 ：\(\text{Since } AD \text{ is vertical, the area of } \triangle ADC \text{ is:}\)

Step 8 ：\(\frac{1}{2} \cdot AD \cdot DC = \frac{1}{2} \cdot 2 \cdot 2 = 2\)

Step 9 ：\(\text{The area of the entire quadrilateral is:}\)

Step 10 ：\(\triangle ABC + \triangle ADC = 2 + 2 = \boxed{4}\)