First, the calculation method:

1, trapezoidal area formula: (upper bottom+lower bottom) × height ÷2.

Expressed in letters: (a+b)×h÷2? 2. The area formula of trapezoid

2: centerline × height? Expressed in letters: L H (L stands for the length of neutral line)

Second, trapezoidal:

A trapezoid is a quadrilateral with only a set of parallel opposite sides. Parallel sides are called trapezoidal bottoms: the longer bottoms are called bottoms, and the shorter bottoms are called bottoms; The other two sides are called waist; The vertical section sandwiched between the two base sides is called the height of the trapezoid. A trapezoid whose waist is perpendicular to the bottom is called a right-angled trapezoid. An isosceles trapezoid is called an isosceles trapezoid.

Third, commonly used auxiliary lines:

1. Zogao (determined according to the actual topic).

3. Translate the diagonal.

4. Stretch your waist at a point in the opposite direction.

5. Take the midpoint of one waist, connect the two ends of the other waist and extend it.

6. Take the midpoint of two bottoms and make a parallel line between two waists through the midpoint of one bottom.

7. Take the midpoint of the two waists and connect them into the center line.

How to learn mathematics well;

First of all, establish a good foundation:

Learning mathematics needs to establish a good foundation and master basic mathematical concepts and operation skills, so as to better understand and master advanced mathematical knowledge.

Second, more hands-on practice:

Learning mathematics requires more hands-on practice. By doing problems, you can deepen your understanding and mastery of mathematical knowledge, and at the same time you can exercise your computing ability and logical thinking ability.

Third, think more:

Learning mathematics requires more thinking. Through thinking, we can understand and master mathematical knowledge, and at the same time cultivate our own mathematical literacy and innovation ability.

Fourth, ask for help:

In the process of learning mathematics, if you encounter difficulties, you can seek the help of teachers or classmates, or consult relevant materials or websites to get more help and guidance.

Fifth, pay attention to the method:

Learning mathematics needs to pay attention to methods and master some problem-solving skills and strategies, so as to learn and master mathematics knowledge more effectively.