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Answer :
Given,
Diameter of upper circular end of frustum part = 18 cm
So, radius (r1) = 9 cm
Now, the radius of the lower circular end of frustum (r2) will be equal to the radius of the circular end of the cylinder
So, r2 = \(\frac{8}{2} \) = 4 cm
Now, height (h1) of the frustum section = 22 - 10 = 12 cm
And,
Height (h2) of cylindrical section = 10 cm (given)
Now, the slant height will be, \( l \ = \ \sqrt{(r_1 \ - \ r_2)^2 \ + \ (h_1)^2} \)
Or, l = 13 cm
Area of tin sheet required = CSA of frustum part + CSA of cylindrical part
\( = \ (r_1 \ + \ r_2)l \ + \ 2 \pi r_2 h_2 \)
Solving this we get,
Area of tin sheet required = 782 × \( \frac{4}{7} \) cm2