A roughly circular lake is 15m across and averages a depth of 1.5m. How much water does it contain in both litres and gallons? Show workings :)

1. Area of the lake: Pi x r x r = 3.14 x 7.5m x 7.5m
= 176.625m squared
2. Cubic area: Area x Depth = 176.625 x 1.5
= 264.94 m cubed
3. As there are roughly 1000 liters of water per meter cubed, the amount of water would be 264937 litres.
4. As 1 gallon equates to 3.8 litres, there would be 69720 gallons of water in the dam.

Workings OK?
https://extension.psu.edu/pond-measurements-area-volume-and-residence-time

I used the US gallon equivalent, so to convert to UK measurements the dam would contain 58875 gallons.
Probably shouldn't have put a link to the UK conversion, sorry...

4. As 1 gallon equates to 3.8 litres, there would be 69720 gallons of water in the dam

1 gallon, 8 pints, is equal to approx 4.5l. At least it is here in the UK. (8pt = 4546.1mL)

1pint is 20 flozs

"The gallon (abbreviation "gal"), is a measure of volume that was used in many parts of Western Europe and is still used in the United States. Historically its value differed depending on locality and commodity. In most localities it has been replaced by the litre, but three variants in current use: the imperial gallon (? 4.546 L) which since metrication is used colloquially in the United Kingdom and semi-officially within Canada, the United States (liquid) gallon (? 3.79 L), and the lesser-used US dry gallon (? 4.40 L). The gallon, be it the imperial or US gallon, is sometimes found in other English-speaking countries."

https://en.wikipedia.org/wiki/Gallon