What formula is used to find the area of a trapezoid?

The formula used to find the area of a trapezoid is A = 1/2(b1 + b2)h. This formula accounts for the two bases of the trapezoid, which are the parallel sides labeled as b1 and b2. The average of the lengths of these two bases is taken (hence the addition and division by 2), and then this average is multiplied by the height (h) of the trapezoid, which is the perpendicular distance between the two bases.

This formula is specific to trapezoids, where the area calculation needs to take into account the varying lengths of the bases. Other formulas provided do not apply to trapezoids; for instance, A = πr² is used for the area of a circle, A = bh corresponds to the area of a rectangle (where b is the base and h is the height), and A = s² is for the area of a square, where s represents the side length. Therefore, the correct identification and use of the trapezoid area formula is crucial for accurately calculating the area in relevant geometric problems.