Răspunsuri

2014-09-25T20:02:08+03:00
Trapezul este isoscel, deci are unghiurile alaturate unuei baze congruente.

m(\widehat{ADC})=m(\widehat{DCB})=\alpha^{\circ}+\beta^{\circ}

m(\widehat{DAB})=m(\widehat{ABC})=180^{\circ}-(\alpha^{\circ}+\beta^{\circ})
Cel mai inteligent răspuns!
2014-09-25T20:34:30+03:00
AD=DC=>m(<DAC)=m(<ACD)=alfa
m(<ADC)=180-2alfa
DC||AB=><DCA=<BAC=>m(<BAC)=alfa
m(<ABC)=360-2alfa-(180-2alfa)-alfa-beta=180alfa-beta
In concluzie:
m(A)=2alfa
m(<B)=180-alfa-beta
m(C)=alfa+beta
m(D)=180- 2alfa