Use the formula:
[tex]A(x_A;\ y_A);\ B(x_B;\ y_B)\\\\|AB|=\sqrt{(x_B-x_A)^2+(y_B-y_A)^2}[/tex]
We have:
[tex]A(21;\ -32);\ B(-3;\ -25)[/tex]
substitute
[tex]|AB|=\sqrt{(-3-21)^2+(-25-(-32))^2}=\sqrt{(-24)^2+7^2}\\\\=\sqrt{576+49}=\sqrt{625}=25[/tex]
Answer: 25 units.
