$P=4\pi r^2$  

$V=\frac{4}{3}\pi r^3$  

 

$a)r=3cm$  

$P=4\cdot \pi \cdot 3^2=36\pi c{m}^2$ $P=4\cdot \pi \cdot 3^2=36\pi c{m}^2$  

$V=\frac{4}{3}\cdot \pi \cdot 3^3=$   $36\pi c{m}^3$  

 

$b)r=17cm$  

$P=4\cdot \pi \cdot {17}^2=1156\pi c{m}^2$  

$P=\frac{4}{3}\cdot \pi \cdot {17}^3=\frac{19652}{3}\pi c{m}^3$  

 

$c)r=1,4dm$  

$P=4\cdot \pi \cdot {\left(1,4\right)}^2=$   $7,84\pi d{m}^2$  

$V=\frac{4}{3}\cdot \pi \cdot {\left(1,4\right)}^3=$   $\frac{10,976}{3}\pi d{m}^3$