Ma straduiesc sa fac punctul c), daca imi iese o sa editez intrebarea.
[tex]a)A_{ABCD} =2\cdot A_{ADB}= 2\cdot \dfrac{DE\cdot AB}{2} = DE\cdot AB\\\text{Prin urmare:}\\ 24= 3\cdot AB\\AB=8\ cm\\P_{ABCD}=AB+BC+CD+AD\\P_{ABCD}=8+6+8+6=28\\P_{ABCD}= 28~ cm\\\\b)\text{In }\Delta ADE~ dr: m(<AED)=90\textdegree \}\\ ~~~~~~~~~~~~~~~~~~~~~~~AD=6~ cm~~~~~~~~~\}\Rightarrow \sin (<BAD)=\dfrac{DE}{AD}=\dfrac{3}{6}=\dfrac{1}{2}\\~~~~~~~~~~~~~~~~~~~~~~~~DE=3~ cm~~~~~~~~\}\\\text{Prin urmare } m(<BAD)=30\textdegree[/tex]
