Question

A hollow right circular cylinder with height $8$ cm and base radius $7$ cm is opened out into a rectangle. What are the length and breadth of the rectangle respectively ?

• A. $22$ cm, $16$ cm
• B. $44$ cm , $8$ cm
• C. $22$ cm, $8$ cm
• D. $44$ cm, $16$ cm

Answer 1

The correct option is B $44$ cm , $8$ cm

Radius of base$=7cm$, Height$=8cm$

After opening, circumference of base=length of sheet

Length$=2\pi r=2\times \frac{22}{7}\times 7=44cm$

And breadth =height$=8cm$