Question

fie un trapez isoscel masura unghiuyluiC=60 baza mare =12 si baza mica =6 aflati aria si perimetru trapezului

Answer 1

notam trapezul ABCD
AB=6
CD=12
m(<BCA)=60⁰
ducem BF_I_DC
FC=(12-6)/2=3
cos 60⁰=1/2
FC/BC=1/2
3/BC=1/2
BC=6 cm
Ptrapez=12+6+6×2=30 cm

sin 60⁰=√3/2
BF/BC=√3/2
BF/6=√3/2
BF=6√3/3=3√3 cm
A=(6+12)×3√3/2=27√3 cm²