$\text{I.}$

$\text{Zapisujemy pole osobno dla kaz˙dego troˊjkąta:}$

$\text{P}=\frac{1}{2}\cdot \text{c}\cdot \text{r}+\frac{1}{2}\cdot \text{a}\cdot \text{r}+\frac{1}{2}\cdot \text{b}\cdot \text{r}$

$\text{P}=\frac{1}{2}\text{r}\left(\text{c}+\text{a}+\text{b}\right)$

$\text{Odp. B, C}$

 

$\text{II.}$

$\text{P}=\frac{1}{2}\cdot 20\text{cm}\cdot 4\text{cm}+\frac{1}{2}\cdot 16\text{cm}\cdot 4\text{cm}+\frac{1}{2}\cdot 12\text{cm}\cdot 4\text{cm}=40{\text{cm}}^2+32{\text{cm}}^2+24{\text{cm}}^2=96{\text{cm}}^2$

$\text{Odp. D, C}$