The capacity of tank express the volume of the water found in the tank.
The shape of the tank is a cylinder, therefore you need to remember the formula of the volume of the cylinder.
Volume = Area of the base * the height of cylinder
Area of the circle base = `(pi*D^2)/4 ` (D is the diameter of the circle base of the water tank).
To find D, you need to know the value of Area.
Find out the value of the area from the volume formula but remember that you must work with the same units of measure: 1m^3 = 1000L and 1kL = 1000 L => 8kL = `8m^3`
`8m^3` = Area of the base*1.8 m
Area of the base = `(8m^3)/(1.8 m)= 4.44 m^2`
You can find D.
`4.44 m^2 = pi*D^2/4 =gt D^2 = 4*4.44 m^2/pi`
Take `pi` `~~` 3.14
D = `sqrt (5.661)`
D `~~` 2.379 m
ANSWER: The diameter of the circle base of water tank is D `~~ ` 2.379 m.