Question

A square of side 28 cm is folded into a cylinder by joining its two sides. Find the base area of the cylinder thus formed.

Area of square = Total surface area of cylinder

(28)² = 2πrh

= 2 × 22 × r × 28

`r = ((28)^2 xx 7)/(2 xx 22 xx  square)`

`r = square/11`

Base area of cylindesr = πr²

= `22/7 xx 49/square xx square/11`

= `square/square` cm²

Answer 1

Area of square = Total surface area of cylinder

(28)² = 2πrh

= 2 × 22 × r × 28

\[r = \frac{(28)^2 \times 7}{2 \times 22 \times \boxed{28}}\]

`r = (28 xx 7)/(2 xx 22)`

`r = (14 xx 7)/22`

\[r = \frac{\boxed{49}}{11}\]

Base area of cylindesr = πr²

= \[\frac{22}{7} \times \frac{49}{\boxed{11}} \times \frac{\boxed{49}}{11}\]

= `22/11 xx 49/7 xx 49/11`

= `2 xx 7 xx 49/11`

= \[\frac{\boxed{686}}{\boxed{11}}\] cm²