Question

Find the surface area of the cylinder and round to the nearest tenth and its recommended that you use pie or 3.14 also the radius is half the diameter

Answer 1

$\begin{gathered} {\underline{\boxed{ \rm { \purple{Surface \: \: area \: = \: 2 \: \pi \: r \: h \: + \: 2 \: \pi \: {r}^{2} }}}}}\end{gathered}$

• r represents radius of cylinder.

• h denotes height of cylinder.

Solution

$\large{\bf{{{\color{navy}{h \: = \: 2 \: ft. }}}}}$

$\bf \large \longrightarrow \: \: r \: = \: \frac{Diameter}{2}$

$\bf \large \longrightarrow \: \: r \: = \: \frac{2}{2}$

$\bf \large \longrightarrow \: \: r \: = \: \cancel\frac{2}{2} \: ^{1}$

$\large{\bf{{{\color{navy}{r \: = \: 1 \: ft. \: }}}}}$

☛ Now , Substuting the values

$\bf \hookrightarrow \: \: \: 2 \: \times \: 3.14 \times \: 1 \: ft \: \times \: 2 \: ft \: + \: 2 \: \times \: 3.14 \: \times \: {(1 \: ft)}^{2}$

$\bf \hookrightarrow \: \: \:6.28 \: ft \: \times \: 2 \: ft\: \: + \: 6.28 \: ft$

$\bf \hookrightarrow \: \: \:12.56 \: {ft}^{2} \: + \: 6.28 \: ft$

$\bf \hookrightarrow \: \: \:18.84 \: {ft} \: ^{2}$

Hence , the surface area of cylinder is 18.84 ft²

Round to the nearest 10 of 18.84 is 18.8

Answer 2

Diameter=d=2ft

• Radius=d/2=2/2=1ft
• Height=h=2ft

We know

$\boxed{\sf Lateral\:Surface\:Area=2πrh}$

$\\ \sf\longmapsto Lateral\: Surface\:Area=2\times 3.14\times 2\times 1$

$\\ \sf\longmapsto Lateral\;Surface\:Area=4(3.14)$

$\\ \sf\longmapsto Lateral\:Surface\:Area=12.56ft^3$