The distance between two points (x₁, y₁) and (x₂, y₂) can be calculated using the formula:
[tex]d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]From the problem, we identify:
[tex]\begin{gathered} (x_1,y_1)=(7,2) \\ \\ (x_2,y_2)=(1,-1) \end{gathered}[/tex]a.
Using the formula, we calculate the exact length of the segment PQ (which is equal to the distance between the points P and Q):
[tex]\begin{gathered} d=\sqrt{(1-7)^2+(-1-2)^2}=\sqrt{(-6)^2+(-3)^2}=\sqrt{36+9}=\sqrt{45} \\ \\ \therefore d=3\sqrt{5} \end{gathered}[/tex]b.
From the previous answer, the approximate length is:
[tex]\therefore d\approx6.7082[/tex]