What are the area formulas for the first to fifth grades of primary school mathematics?

The perimeter of a rectangle = (length+width) ×2 The perimeter of a square = side length ×4.

Rectangular area = length x width square area = side length x side length

Parallelogram area = base × height trapezoid area = (upper base+lower base) × height ÷2

Area of triangle = base × height ÷2

The surface area of a cuboid = (length× width+length× height+width× height) ×2.

Surface area of cube = side length × side length ×6

Volume of cuboid = length× width× volume of high cube = side length× side length× side length.