A cylindrical bucket with a bottom radius of 20 cm is filled with water. Now a cone iron block with a bottom area of 314 square cm is submerged in the water. The water surface rises by 8 cm. How high is the cone iron block? If you want to use + - × / to express, * doesn't look good

A cylindrical bucket with a bottom radius of 20 cm is filled with water. Now a cone iron block with a bottom area of 314 square cm is submerged in the water. The water surface rises by 8 cm. How high is the cone iron block? If you want to use + - × / to express, * doesn't look good

If we put in an iron block, it is equal to adding water with the same volume as the iron block, then we can deduce the volume of the iron block through the rising volume of the water surface. The rising volume is V1 = π * R1 * R1 * H1 = 3.14 * 20 * 20 * 8, and the iron block is a cone, then V2 = (1 / 3) s bottom * h2 = (1 / 3) * 314 * h2v1 = V2, that is, 3.14 * 20 * 20

9-1=8;16-4=12;25-9=16;36-16=20…… N is a positive integer, which is represented by the formula of n

(n+2)²-n²
=4n+4

9-1 = 8; 16-4 = 12; 25-9 = 16; 36-16 = 20.. these formulas reflect some rules among positive integers, if n is a positive integer
Let's use the formula of n to express this formula as thank you

(n+2)²-n²=4n+4=4(n+1)