Question

the total surface area of a cone whose radius is r/2 and slant height 2l is

Answer 1

the answer was tricky i think it will be 11r(3+r)cm square

Answer 2

New total surface area :  ($\frac{\pi \times r^{2} }{4})   + \pi \times rl$

Step-by-step explanation:

Total surface area of a cone = Area of the curve + Area of the base

S, TSA  = π$r^{2}   + \pi \times rl$

Now, here, R = r/2 and  L =2l

So, TSA

:   π$R^{2}   + \pi \times RL$  

= π$(\frac{r}{2} )^{2}   + \pi \times \frac{r}{2} \times 2l$

= π$\frac{r^{2} }{4}  + \pi \times rl$

New total surface area :  ($\frac{\pi \times r^{2} }{4})   + \pi \times rl$

So, the new total surface area = Older Curved Surface area + (Base area /4)