Panjang bc adalah.....cm

Aturan Sinus
..
AD/SinC = AC/SinD
10/Sin45° = AC/Sin30°
10/½√2 = AC/½
10/√2 = AC
5√2 = AC

Selanjutnya, Aturan Cosinus

BC = √AB²+AC² - 2.AB.AC CosA
= √(10√2)²+(5√2)²-2(10√2)(5√2)Cos60°
= √200+50-100
= √150
= √25×6
= 5√6

★D★