Question

If \(\vec{a},\; \vec{b},\;\vec{c}\) represent the sides of Δ show that \(\vec{a}\times\vec{b} = \vec{b}\times\vec{c} = \vec{c} \times\vec{a}\) hence derive sine formula.

Answer 1

Since \(\vec{a},\; \vec{b},\;\vec{c}\) are the sides of a triangle 

\(\vec{a} + \vec{b} + \vec{c} = 0\)