Question

Prob 3 și 4 plssss dau ​

Answer 1

3)

$\it Din\ enun \c{\it t}\ \Rightarrow\ BC=1m,\ \ AB=1m,\ \ BE=1,5-1=0,5m\\ \\ \\ CD||AE\ \Rightarrow \Delta AEF\ \sim\ \Delta BEC \Rightarrow \dfrac{AE}{BE}=\dfrac{AF}{BC} \Rightarrow \dfrac{1,5}{0,5}=\dfrac{AF}{1} \Rightarrow\\ \\ \\ \Rightarrow AF=\dfrac{\ \ 1,5^{(10}}{0,5}=\dfrac{15}{5}=3m$

4)  

Transformăm lungimile laturilor în hm, adică:

AC=3hm,  AB=4hm,  BC=5hm.

$\it Not\breve am\ AD=x,\ BD=y\ \Rightarrow CD=5-y$

Scriem egalitatea celor două perimetre:

$\it x+y+4=x+5-y+3 \Rightarrow 2y=4 \Rightarrow y=2\ hm$

$\it \mathcal{A}_{ABD} =\dfrac{1}{2}AB\cdot BD\cdot sin B = \dfrac{1}{2}\cdot4\cdot2\cdot\dfrac{3}{5}=\dfrac{12}{5}=2,4\ hm^2=24000m^2$