Răspuns :
Lm in trapez=semisuma bazelor trapezului. lm=(B+b)/2;inlocuim b=3cm, lm=6 cm;
6=(B+3):2; B+3=6 x 2; B+3=12; B=12-3; B=9 cm
Lm in trapez=semisuma bazelor trapezului. lm=(B+b)/2;inlocuim b=3cm, lm=6 cm;
6=(B+3):2; B+3=6 x 2; B+3=12; B=12-3; B=9 cm