Current location - Training Enrollment Network - Mathematics courses - What are the mathematical formulas that must be memorized in the first volume of the first day of junior high school?
What are the mathematical formulas that must be memorized in the first volume of the first day of junior high school?
The formula for reciting mathematics in the first volume of the first day of junior high school is as follows:

1. The circumference of a rectangle = (length+width) ×2, and C=(a+b)×2?

Second, the perimeter of the square = side length ×4, C=4a?

Third, the area of the rectangle = length × width, S=ab?

4. area of a square = side length × side length, S=a.a=? a^2

Verb (abbreviation of verb) Area of triangle = base × height ÷2, S=ah÷2?

Six, parallelogram area = bottom x height, S=ah.

Seven, trapezoidal area = (upper bottom+lower bottom) × height ÷2, s = (a+b) H ÷ 2?

Eight, circumference = π× diameter = π× radius× 2, c=πd? =2πr?

Nine, the area of the circle = π× radius× radius? πr ^2