Question

what is the tsa of a cone whose radius is r/2 and slant height is 2l​

Answer 1

see attachment ✌️

hope it helps ✌️

Answer 2

Answer :–

• Total surface area (T.S.A.) of a cone = $\sf\pi r( \frac{r + 4l}{2} )$

Given :–

• Radius of a cone (r) = $\frac{r}{2}$
• Height of a cone (h) = 2l

To Find :–

• Total surface area (T.S.A.) of a cone.

Solution :–

Formula,

• Total surface area of a cone = $\red{\pi r(r + h)}$

Given values are,

• r = $\frac{r}{2}$
• h = 2l

Now,

→ $\sf\pi \times \frac{r}{2} ( \frac{r}{2} + 2l)$

→ $\sf\pi r ( \frac{r + 2l \times 2}{2} )$

→ $\sf\pi r( \frac{r + 4l}{2} )$

Hence, the total surface area (T.S.A.) of a cone is $\sf\pi r( \frac{r + 4l}{2} )$