Question

In triunghiul isoscel ABC ([AB]≡[AC]), D este piciorul bisectoarei unghiului BAC. Sa se calculeze:
a) m (BAC), daca m ( BAD)=18 grade si 41 minute
b) perimetrul ΔABC, daca AB=8 cm si BC=0,3 dm

Answer 1

ΔBAD,mas<D=90
mas<BAD=18 41'   ⇒mas<B=90- 18 41'= 71 19'

ΔABC-isoscel, mas<B=mas<C=71 19'

ΔDAC, mas<D=90
mas<C=71 19'   ⇒mas< DAC=90- 71 19'=18 41'

mas<BAC=mas<BAD+mas<DAC= 18 41' +18 41'= 36 82'= 37 22'

b)ΔABC-isoscel,AB=AC
BC=0,3dm=3cm
P=2AC+BC=2*8+3=16+3=19