Question

if radius of base of a cylinder is double and its height is reduced to half what will happen to its curved surface area and total surface area and volume​

Answer 1

$\huge\mathfrak\color{indigo}solution$

Let the radius of the cylinder be =r unit.

And the height be =h unit.

If the radius be doubled and height be reduced to half,

then the curved surface area will be

$= 2\pi \: rh \\ = 2\pi \times 2r \times \frac{h}{2} \\ = 2\pi \: rh$

then, the total surface area will be

$2\pi r(h + r) \\ = 2\pi \times 2r( \frac{h}{2} + 2r) \\ = 2\pi \times 2r ( \frac{h + r}{2} ) \\ = 2\pi \: r(h + r)$

then, the volume will be

$= \pi \: {r}^{2} h \\ = \pi \times (2 {r})^{2} . \frac{h}{2} \\ = \pi \times 4 {r}^{2} . \frac{h}{2} \\ = \pi \times 2 {r}^{2} h$

Hence,the curved surface area and the total surface area remains same.

But the volume changes.

$\huge\mathfrak\color{indigo}hope \: it \: helps \: uhh$