Question

cum se face ex asta, help va rog:))

Answer 1

Construim BP⊥AC
triunghiul BAP; m(∡P)=90°=>sin 60°=√3/2=BP/AB=>√3/2=BP/4=>BP=2√3 cm
                                              cos 60°=1/2=AP/AB=>1/2=AP/4=>AP=2 cm
triunghiul BPC; m(∡P)=90°=>(T.P.) BP²+PC²=BC²=>BC=√28=2√7 cm

Answer 2

BC²=AB²+AC²-2AB×AC×cos60°
BC²=16+36-2×4×6×1/2
BC²=16+36-24
BC²=28
BC=√28=2√7 cm