The total surface area of a solid cylinder whose radius is r cm and height is $\frac{r}{2}$ cm ( in cm2) is :
Answer & explanation
Correct answer: option 3
Total surface area of cylinder = 2πr ( r + h )
= 2 × π × r ( r + \(\frac{r}{2}\) )
= 2 × π × r × \(\frac{3r}{2}\)
= 3πr²