The circumference of the bottom surface of a cone-shaped fertilizer pile is 12.56 meters, and the height is 1.8 meters How many hectares of land can this pile of fertilizer apply? O (∩) O thank you, If the fertilizer is 20 cubic meters per hectare

The circumference of the bottom surface of a cone-shaped fertilizer pile is 12.56 meters, and the height is 1.8 meters How many hectares of land can this pile of fertilizer apply? O (∩) O thank you, If the fertilizer is 20 cubic meters per hectare

Bottom radius: 12.56/3.14/2 = 2 (m)
Cone volume: 2x2x3.14x1.8x3 1 / 3 = 7.536 (M3)
I didn't understand!

The circumference of the bottom surface of a cone-shaped rice pile is 12.56 meters. If the weight of each cubic meter of rice is about 300 kg, how many kg does this pile of rice weigh?

Radius 12.56 ÷ (2x3.14) = 2m
heavy
1/3x2x2x3.14x3x300
=12.56x300
=3768kg

The circumference of the bottom surface of the cone-shaped rice pile is 12.56 meters, the height is 3 meters, and how much is the weight of 5000 kg per cubic meter

(12.56/3.1416*2)²*3.1416*3/3
=12.5536
12.5536 * 5000 = 62768kg