intr-un patrulater ABCD se duce diagonala AC,se da : m(DAB)=85 de grade,m(DAC)=28 de grade,m(D)=105,m(ACB)=60 de grade
Calculati masurile unghiurilor : CAB,B,ACD,DCB
m(CAB)=m(BAD)-m(CAD)=85-28=57; m(ACD)=180-m(CAD)-m(ADC)=180-28-105=47; m(B)=180-m(ACB)-m(BAC)=180-60-57; m(DCB)=m(ACD)+m(ACB)=47+60=107; Sper sa nu fi gresit ceva