Question

Ma puteti ajuta va rog:
Sa se calculeze lungimea razei cercului circumscris triunghiului ABC, daca A=$\frac{ \pi}{4}$, B=$\frac{ \pi}{6}$ si AB=6.

Answer 1

A=π/4=45⁰
B=π/6=30⁰
AB=6
ducem AD_I_BC
sin 30⁰=AD/AB
1/2=AD/6
AD=3
BD=√(6²-3²)=√27=3√3
AD²=BD×DC
9=3√3×DC 
DC=9/3√3=√3
BC=3√3+√3=4√3
AC=√[3²+(√3)²]=√(9+3)=2√3
R=AB×BC×AC/4A
A=4√3×3/2=6√3
AB×BC×AC=6×4√3×2√3=144
R=144/4×6√3=144/24√3=6/√3=6√3/3=2√3 cm