Skorzystamy ze wzoru:

$\left|AB\right|=\sqrt{{\left(x_A-a\right)}^2+{\left(y_A-b\right)}^2-r^2}$ $\left|AB\right|=\sqrt{{\left(x_A-a\right)}^2+{\left(y_A-b\right)}^2-r^2}$   

A więc:

$\left|AB\right|=\sqrt{{\left(-8\right)}^2+{10}^2-50}=\sqrt{64+100-50}=\sqrt{164-50}=\sqrt{114}$