Answer:
The volume of the observatory is 497.43

Explanation:
i) The diameter of the floor is 10 feet. The floor is circular and has a radius,
r =
= 5 feet.
Therefore the area of the circular floor of the observatory
=
= 3.14159 ×
= 78.54

ii) The observatory is made up of two parts
a) 3 foot tall cylinder
∴ volume of cylinder =
× h
= 78.54 × 3
= 235.62

b) hemisphere =
×
= 0.6667 × 78.54 × 5 = 261.81

c) Therefore the total volume of the observatory is = a) + b)
= 235.62 + 261.81 = 497.43
