Question

find the radius of a cylinder whose hight is 14cm and volume is 891cm√​

Answer 1

Answer:

Radius of cylinder is 4.5 cm .

Step-by-step explanation:

Given :

• Height of cylinder is 14 cm.
• Volume of cylinder is 891 cm³.

To find :

• Radius of cylinder.

Solution :

We know,

• Volume of cylinder = πr²h

[Where, r is radius and h is height of cylinder]

Now, Put given volume and height of cylinder in formula :

$\implies \sf 891 = \pi r^{2} h$

$\implies \sf 891 = \dfrac{22}{7} \times r^{2} \times 14$

$\implies \sf 891 = \dfrac{308}{7} \times r^{2}$

$\implies \sf 891 = 44 \times r^{2}$

$\implies \sf \dfrac{891}{44} = r^{2}$

$\implies \sf r^{2} = 20.25$

$\implies \sf r = \sqrt{20.25}$

$\implies \pmb{\sf r = 4.5}$

Therefore,

Radius of cylinder is 4.5 cm.

________*

Three more formulas of cylinder are :

1. Total surface area of cylinder is 2πr(r + h) or 2πr² + 2πrh.
2. Curved surface area or Lateral surface area of cylinder is 2πrh.
3. Base area of cylinder is πr².

• Where, In all formulas r is radius and h is height of cylinder.

Answer 2

Step-by-step explanation:

$</p><p></p><p> </p><p>.</p><p></p><p>{\implies}{ \boxed{\mathbb{\red{given \: that }}}}\\ height =14 \\ volume = 891cm^{3} \\ </p><p></p><p> </p><p></p><p></p><p>{\implies}{ \boxed{\mathbb{\blue{step \: by \: step \: explaniation }}}}\\ \\ </p><p></p><p> </p><p>.</p><p></p><p>{\implies}{ \boxed{\mathbb{\pink{ using \: formula}}}} \: \\ </p><p></p><p> </p><p></p><p>{\implies}{ {\mathbb{\red{volume \: = \pi {r}^{2} h }}}}\\ 891 = \frac{22}{7} \times {r}^{2} \times 14 \\ 891 = 22 \times 2 \times {r}^{2} \\ 891 = 44 {r}^{2} \\ {r}^{2} = \frac{891}{44} \\ {r}^{2} = 20.25 \\ = r\sqrt{20.25} \\ r </p><p></p><p> </p><p></p><p></p><p>{\implies}{ \boxed{\mathbb{\green{= 4.5cm}}}}$