A rectangular paper 11 cm by 8 cm can be exactly wrapped to cover the

1.	A rectangular paper 11 cm by 8 cm can be exactly wrapped to cover the curved surface of a cylinder of height 8 cm . What is the volume of the cylinder ?
Answer» Area of the curved surface = Area of the rectangle = (11 × 8) cm² = 88 cm². ⇒ 2πrh = 88 cm ⇒ 2 × \(\frac{22}{7}\times{r}\times8 = 88\) ⇒ r = \(\frac{88\times7}{44\times8}=\frac74\) cm. ∴ Volume of the cylinder = πr²h = \(\frac{22}{7}\times\frac74\times\frac74\times8\) = 77 cm³ .

A rectangular paper 11 cm by 8 cm can be exactly wrapped to cover the curved surface of a cylinder of height 8 cm . What is the volume of the cylinder ?

Answer»

Area of the curved surface = Area of the rectangle = (11 × 8) cm² = 88 cm².

⇒ 2πrh = 88 cm ⇒ 2 × \(\frac{22}{7}\times{r}\times8 = 88\) ⇒ r = \(\frac{88\times7}{44\times8}=\frac74\) cm.

∴ Volume of the cylinder = πr²h = \(\frac{22}{7}\times\frac74\times\frac74\times8\) = 77 cm³ .