Final answer:
The best formula to calculate the cross-sectional area of a trapezoid is (Base1 + Base2) / 2 × Height. This formula is derived from the formula for the area of a triangle.
Step-by-step explanation:
The best formula to calculate the cross-sectional area of a trapezoid is (Base1 + Base2) / 2 × Height, which corresponds to option 2. This formula is derived from the formula for the area of a triangle, which is 1/2 × base × height. Since a trapezoid can be divided into two triangles, we can calculate the area of each triangle and then sum them up.