Question

the interior of a building is in the form of a right circular cylinder of diameter 4.2m and height 4m is surmounted by a cone the vertical height of the come is 2.4m find its outer surface area

Answer 1

heya!!


refer to given attachment please

Answer 2

Answer:

$Outer \: surface \: area \\of \:the \: building\\(A)=73.788 \:m^{2}$

Step-by-step explanation:

Dimensions of the circular cylinder:

Diameter (d)=4.2 m

$Radius (r)=\frac{d}{2}\\=\frac{4.2}{2}\\=2.1\:m$

Height (H)=4 m

Dimensions of a cone :

radius (r)= 2.1m

height (h)= 2.4 m

slant height (l)=√r²+h²

=√(2.1)²+(2.4)²

=√4.41+5.76

=√10.17

≈ 3.18 m

Now,

$Outer \: surface \: area \\of \:the \: building\\(A)=Curved \: surface \: area \: of\\ \: the \: cylinder\\ +curved \: surface \: area \: of \: the \: cone$

$\implies A= 2\pi rH+\pi rl\\=\pi r(2H+l)\\=\frac{22}{7} \left(2\times 4+3.18\right)\\=22\times 0.3 \times 11.18\\=73.788 \: m^{2}$

Therefore,

$Outer \: surface \: area \\of \:the \: building\\(A)=73.788 \:m^{2}$

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