Find the type of triangle ABC formed whose vertices are A$\displaystyle (1, 0)$, B$\displaystyle (-5, 0)$ and C$\displaystyle (-2, 5)$.

\[\begin{aligned} & A(1,0) \quad B(-5,0) \quad C(-2,5) \\ & A B=\sqrt{(-5-1)^{2}+(0-0)^{2}}=6 \\ & B C=\sqrt{(-5+2)^{2}+(0-5)^{2}}=\sqrt{34} \\ & C A=\sqrt{(1+2)^{2}+(0-5)^{2}}=\sqrt{34} \\ & \therefore B C=C A \\ & \text { So, } \triangle A B C \text { is isosceles. } \end{aligned} \]