[tex]CO-ORDINATE \: \: GEOMETRY \\ \\ \\
We \: are \: given \: the \: co - ordinates \: \\ \\ \: B \: (8 , - 7) \: = (x1,y1) \: \: \: \: \: and \\ \\ C \: ( - 4. - 2) = (x2,y2) \\ \\ \\ Using \: distance \: formula \: - \: \: \\ \\ BC = \sqrt{ {(x2 - x1)}^{2} + {(y2 - y1)}^{2} } \\ \\ BC = \sqrt{ { ( - 4 - 8)}^{2} + {( - 2 + 7)}^{2} } \\ \\ BC = \sqrt{ {( - 12)}^{2} + {5}^{2} } \\ \\ BC = \sqrt{144 + 25} \: \: = \: \: \sqrt{169 } \\ \\ \\ \\ || \: BC \: \: = \: \: 13 \: \: units \: \: | | \: \: \: \: \: \: Ans.[/tex]
