The formula to find the distance, d, between two points is
![d=\sqrt[]{(x_2-x_1)^2+(y_2-y_1)^2}](https://img.qammunity.org/2023/formulas/mathematics/college/be685jmxw05hm2tq94m5iuge2xjynn1hfn.png)
Taking (1,1) as the coordinates of the first point and (4,5) as the coordinates of the second point as shown below,

Substitute the coordinates into the formula for the distance between two points
![\begin{gathered} d=\sqrt[]{(4-1)^2+(5-1)^2} \\ d=\sqrt[]{3^2+4^2} \\ d=\sqrt[]{9+16} \\ d=\sqrt[]{25} \\ d=5\text{ units} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/4696iv7nsdjfw7hgrqclx4pyc60lgddf0m.png)
Hence, the distance between the two points is 5 units