ABCD trapez isoscel deci AD=BC=40mm=4cm
Perimetrul =AB+BC+CD+AD=4cm+4cm+4cm+6cm=18cm
ABCD trapez isoscel deci AC=BD diagonale egale
BD=BO+OD=0,3dm+0,07m=3cm+7cm=10cm
AC+BD=10cm+10cm=20cm
masura ABC=masura DAB=80 grade trapez isoscel
masura ADC este180-masura DAB=180-80=100
B=baza mare
b=baza mica
(B+b)/2=16
B+b=16*2=32 cm
(B-b)/2=4
B-b=4*2=8cm
B=b+8
Inlocuim in prima relatie
b+8+b=32
2b=32-8
2b=24
b=24/2
b=12cm
B=b+8=12+8=20cm