Garden pond

The concrete garden pond has the bottom shape of a semicircle with a diameter of 1.8 m and is 72 cm deep. Daddy wants to make it surface. How many liters of water are in the pond if the water level is 33 cm?

Correct answer:

V =  419.87 l

Step-by-step explanation:

$$\begin{gathered} D=1.8\text{m}\to \text{dm}=1.8\cdot 10\text{dm}=18\text{dm} \\ h=33\text{cm}\to \text{dm}=33:10\text{dm}=3.3\text{dm} \\ r=D/2=18/2=9\text{dm} \\ {S}_1=\pi \cdot r^2/2=3.1416\cdot 9^2/2\doteq 127.2345{\text{dm}}^2 \\ 1d{m}^3=1l \\ V=S_1\cdot h=127.2345\cdot 3.3=419.87\text{l} \end{gathered}$$

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