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trapezul dreptunghic ABCD(AB||CD,m(A)=m(D)=90°) AB=8cm DC=20cm A BEC=54cm² BEperpendicular pe DC,E apartine (DC)
a) [BE]=?
b) aria ABCD=?
c) aria BAC=?
Va rooog dau corana pt rezolvarea corecta


Răspuns :

tr dreptungjicBEC- EC=CD-AB=12;; aria=c1*c2/2=>54=12*BE/2=>12BE=108=>BE=9. b) aruia trapez=( b+B)*h/2=(20+8)*9/2=126. c) aria tr ADC=c1*c2/2=9*20/2=90=> aria tr BAC= aria trapez- aria tr ADC=126-90=36