Basketball must be a perfect circle, orange in color, and the outer skin must be made of leather, rubber or synthetic materials, weighing 600 to 650 grams and having a circumference of 75 to 78 centimeters. The degree of air pressure in the ball falls on the playing field at a height of about 1.8m from the bottom of the ball, and its rebound height shall not be lower than 1.2m or higher than 1.4m from the top of the ball. Volleyball weighs 255-346 grams. Its bladder and shell are sewn with leather and canvas. The circumference of the ball is 63, 5-68, 8 cm. According to the rules of football, its circumference is not longer than 70 cm and not shorter than 68 cm. From this, the diameter is calculated to be 22. 293 to 2 1. 656 1 cm.

Length and width of international standard football field

90m long-110m

Width 45 -80 meters

At the beginning of the game, the weight of the ball should not exceed 453 grams or less than 396 grams. After inflation, its pressure should be equal to 0.6- 1. 1 atmospheric pressure (sea level), which is equivalent to 600- 1 100g/cm'. The standard weight of handball is 425-475g.