ANSWER
√10
EXPLANATION
The distance between two points (x1, y1) and (x2, y2) is:
[tex]d=\sqrt[]{(x_1-x_2)^2+(y_1-y_2)^2_{}}[/tex]Points A and B have coordinates: A(0,0) and B(1, 3). The distance between them is:
[tex]\begin{gathered} d=\sqrt[]{(1-0)^2+(3-0)^2} \\ d=\sqrt[]{1^2+3^2} \\ d=\sqrt[]{1+9} \\ d=\sqrt[]{10} \end{gathered}[/tex]