<) A =60 grade => <) BAC = CAD =30 gr
CD ll AD => <)ACD =30 gr. => triungh.ADC =isoscel ;
=> AD =DC =CB
<) A =B =60 gr. => <) C =120 gr. ( <) C=D =120 gr )
<)ACB = C - ACD
ACB = 120 - 30
ACB =90 gr
<)CAB =30 gr. =>BC =AB/2 =10/2 =5 cm
BC=AD=CD =5 cm
P =10+5+5+5 =25 cm