The height of a cone is 3m and the diameter of its base is 8m. Then its

 

$$\begin{gathered} Height of cone\left(h\right)=3 m \\ Base diameter \left(d\right)= 8 m \\ Radius of base\left(r\right) = 4 m \\ Slant height=\sqrt{(h^2+{\pi }^2)}=\sqrt{(3^2+4^2)}=5 m. \\ CSA of cone= \pi rl=\frac{22}{7}\times 4\times 5=62.85 m^2 \\ TSA of cone=\pi r(l+r)=\frac{22}{7}\times 4(5+4)=113.1 m^2 \\ Volume of cone=\frac{1}{3}\pi r^{2}h=\frac{1}{3}\times \frac{22}{7}\times 4\times 4\times 3=50.28 m^2 \end{gathered}$$