Question

Urgent! Am nevoie de răspuns serios!

Answer 1

Răspuns:

20 cm

Explicație pas cu pas:

poza

Answer 2

$\it \Delta ABC \equiv \Delta MNP\ \Rightarrow\ \begin{cases} \it AB=MN\\ \\ BC=NP\\ \\ AC=MP\end{cases}\\ \\ \\ MN=\dfrac{NP}{2} \Rightarrow AB=\dfrac{NP}{2}\\ \\ \\ MP=\dfrac{MN+NP}{2}=\dfrac{\dfrac{NP}{2}+NP}{2}=\dfrac{3NP}{4}\ \Rightarrow AC=\dfrac{3NP}{4}$

$\it \mathcal{P}_{ABC}=AB+BC+AC \Rightarrow 45=\dfrac{NP}{2}+NP+\dfrac{3NP}{4}\bigg|_{\cdot4} \Rightarrow \\ \\ \\ \Rightarrow 180=2NP+4NP+3NP \Rightarrow 9NP=180\bigg|_{:9} \Rightarrow NP=20\ cm\\ \\ Deci,\ BC=NP=20\ cm$