first determine the distance from point A to B, Point B to C then C to A.
using the formula for distance between two points.
[tex]d= \sqrt{( x_{2}-x_{1})^2+( y_{2}-y_{1})^2 } [/tex]
solve for distance from A to B
[tex]d= \sqrt{( -3-1)^2+( 1-3)^2 } [/tex]
[tex]d=2 \sqrt{5} [/tex] [tex]units[/tex]
solve for distance from B to C
[tex]d= \sqrt{( 2-(-3))^2+( -2-1)^2 } [/tex]
[tex]d= \sqrt{34} [/tex] [tex]units[/tex]
solve for distance from C to A
[tex]d= \sqrt{( 1-(2))^2+( 3-(-2))^2 } [/tex]
[tex]d= \sqrt{34} [/tex] [tex]units[/tex]