1. paralelogram
AB=CD= 10 cm
AD=BC = 6cm
2. AB=CD=6cm
AD=BC = x
perim. = AB + BC +CD +AD= 6cm + x + 6cm + x = 30m
12m + 2x = 30m ; 2x= 30m - 12m = 18m
x = 18m :2 = 9m
laturile : 6m ;9m;6m;9m
3,daca mas<A= 50°
atunci mas<A + mas<B =180°
mas<B =180 ° - 50° =130°
unghiurile 50°;130°;50°;130°