If the radius r of the drum circle and the height h of the drum are unknown, we can measure the circumference l and height h of the drum. If the circumference L of the circle is 2× r× π, then r=l/(2π), and the volume of the drum = bottom area× height =π×l? /(2π)? h .
Extended data:
Such as how to calculate the capacity of a drum? It is known that the height is 35cm and the base diameter is 26cm. How many liters of water can it hold?
Volume = bucket bottom area × height =π×r? h？
=? π×(26/2)? ×35
= 13? ×35π
=59 15π(π is 3. 14)
= 18573. 1cm^3= 18.57l
This barrel can hold about 18.57 liters of water.
References:
Baidu encyclopedia-column