Perhatikan gambar di bawah ini,panjang AB=

AC = 6 cm
< B = 60°

< C = 180° - (< A + < B)
< C = 180° - (90° + 60°)
< C = 180° - 150°
< C = 30°


AC/sin 60° = AB/sin 30°
6/(1/2 V3) = AB/(1/2)
6 × 1/2 = AB × 1/2 V3
3 = AB × 1/2 V3
AB = 3/(1/2 V3)
AB = 3 × 2/V3
AB = 6/V3
AB = 6/V3 × V3/V3
AB = 6V3/3
AB = 2V3 (B)