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ABCD-trapez isoscel cu AB || CD;AB=120 m,CD=60 m,AC perpendicular pe BC,CM perpendicular pe AB ( M apartine AB)
a)MB=?
b) BC=CD


Răspuns :

deci DN=NM=60
AB=AN+NM+MB
120=MN+60+MB
2MB=120-60
2MB=60
MB=30
FACEM PRIN TEOREMA INALTIMII
CM^2=AM*MB
CM^2=(30+60)*30=90*30=2700
=)CM=30 RAD 3 
FACEM PITAGORA 
BC^2=CM^2+MB^2
BC^2=(30 RAD 3)^2+30^2
BC^2=2700+900
BC=3600=)BC=60=CD


eu atata am inteles sper sa fie corect

[tex]a)\\MB=\frac{AB-CD}{2}=30\\ b)\\T.C. in \ \triangle ACB\\ BC^2=AB\cdot BM=120\cdot30=3600\\ BC=60=CD\\ q.e.d. [/tex]