1. The trapezoidal area is equal to the sum of the upper bottom and the lower bottom multiplied by half the height, that is, S=(a+b)×h÷2.

2. Differential product formula method. The trapezoidal area is equal to the difference between the upper bottom and the lower bottom multiplied by half the height, that is, S=(a-b)×h÷2.

3. The midline formula method. The trapezoidal area is equal to the sum of the upper bottom and the lower bottom multiplied by half of the height, that is, S=(a+b)×h÷2.

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Trapezoid is a common geometric figure, and its four sides are upper bottom, lower bottom, left hypotenuse and right hypotenuse. The area of a trapezoid can be calculated by many methods, among which the most common method is to multiply the average length of the upper and lower bottoms by the height.

The characteristic of trapezoid is that its two hypotenuses are equal in length, and its shape can be changed according to the distance between the upper and lower base and the angle between them.

Trapezoids are widely used in architecture, art, engineering and science. In architecture, trapezoid is widely used in structural design, such as building stairs, sidewalks, roofs and so on. In addition, in engineering, trapezoid is often used in mechanical drawing, such as drawing some parts of a machine or describing physical phenomena such as water flow.

Besides its application in the real world, trapezoid also plays an important role in mathematics. For example, in Euclidean geometry, trapezoid is the only parallelogram with four fixed angles, so it becomes the basis of many geometric theorems and inferences. In addition, the formula for calculating the area of trapezoid is also the basis for calculating the area of many other geometric figures, such as parallelogram and triangle.

In addition to the applications and features mentioned above, trapezoid has some interesting properties and phenomena. For example, if two circles are drawn at both ends of the upper bottom of a trapezoid and tangent to both ends of the lower bottom, the radii of the two circles are equal. In addition, if you fold the top and bottom sides of the trapezoid in half, they will intersect at the center and all four corners will become right angles.

In a word, trapezoid is a very interesting and useful geometric figure, which is widely used and occupies an important position in mathematics. Whether in real life or in mathematics, trapezoid is an indispensable geometric concept.