We went with 2 times 3? Well, now we'd be finding Now, the trapezoid isĬlearly less than that, but let's just go with So it would give us thisĮntire area right over there. The area of a figure that looked like- let me do We multiply 6 times 3? Well, that would be the Multiplied this long base 6 times the height 3? So what do we get if Is, given the dimensions that they've given us, what And so this, byĭefinition, is a trapezoid. Where two of the sides are parallel to each other. Either way, you will get the same answer. You can intuitively visualise Steps 1-3 or you can even derive this expression by considering each Area portion and summing up the parts.

Therefore, the area of the Trapezoid is equal to. In Area 3, the triangle area part of the Trapezoid is exactly one half of Area 3 Adding the 2 areas leads to double counting, so we take one half of the sum of smaller rectangle and Area 2ģ. In Area 2, the rectangle area part of the Trapezoid is equal to Area 2 as well as the area of the smaller rectangle. In Area 1, the triangle area part of the Trapezoid is exactly one half of Area 1Ģ. Let's call them Area 1, Area 2 and Area 3 from left to right. Think of it this way - split the larger rectangle into 3 parts as Sal has done in the video. So what Sal means by average in this particular video is that the area of the Trapezoid should be exactly half the area of the larger rectangle (6x3) and the smaller rectangle (2x3).

Volume of a isosceles trapezoid prism