The side length of a square is a. Circumference =4a, area =a×a
The radius of a circle is r, the circumference is 2×=π×r r, and the area is the square of π× r.
The base of the triangle is a, the height on the base is h, and the area is =a×h÷2.
The base of the parallelogram is a, the height of the base is h, and the area = a× h.
The upper base of the trapezoid is a, the lower base is b, the height is h, and the area is =(a+b)×h÷2.
The length, width and height of a cuboid are abc. Sum of sides =4×(a+b+c), surface area =2×(a×b+b×c+a×c), and volume = a× b× c.
The side length of a cube is a, the sum of the side lengths = 12×a, the surface area =6×a squared, and the volume = a.
The radius of the cylinder bottom is r, the height is h, the surface area is 2× π× r× h+π× r square, and the volume is π× r square× h.
The radius of the cone bottom is r, the height is h, and the volume is = 1/3×π×r square× h.