Mathematical formula! ! It's better to be the formula of the Olympic math problem! ! ! For example, a chicken and a rabbit live in the same cage, and a regular triangle knows how to find the area of a side ... well said! ! ! Square: side length × 4 circumference

Side length × side length-area

Rectangle: (length× width )× 2 —— perimeter

Length × width-area

Cube: side length × side length× side length-volume

Side length × side length× 6-surface area

Side length × 12- perimeter

Cuboid: Length× Width× Height-Volume

(L× H+L× H+W× H) ×2- surface area

(Length+Width+Height) ×4

Trapezoid: (upper bottom+lower bottom) × height-area

Circle: π× diameter 2×π× radius-circumference

Pi × radius× radius-area

Semicircle: pi× diameter ÷2+ diameter

2×π× Radius ÷2+ Diameter-Perimeter

Pi × radius× radius ÷2- area

Triangle: base × height ÷2- area

Parallelogram: Length× Width-Area

(length× width )× 2-circumference