Answer:
When calculating the area of a triangle, you multiply the base by the height and then divide the result by 2. This is because a triangle is half of a parallelogram or a rectangle, and these shapes have an area equal to base times height. By dividing by 2, you are finding half of the area of the parallelogram or rectangle.
For a trapezoid, you can find the area by taking the average of the bases and multiplying it by the height. So the formula for the area of a trapezoid is A = (b1 + b2)h/2, where b1 and b2 are the lengths of the two parallel bases and h is the height. There is no need to divide the result by 2 because the formula already takes the average of the bases into account.