the answer will be option B 6.7
Step-by-step explanation: in co-ordinate geometry, let the P(x1, y1) and Q(x2, y2) be two points.
so their distance will be = sqaure root of ((x1 - x2)^2+(y1 - y2)^2)
here we take x1 = 1 , y1 = 2
and x2 = 4 , y2 = 8
so putting the values in the equation we get,
![√((1-4)^2 + (2 - 8)^2)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/1afrbn377h7lpn0f1bwq3ltmax4a08n77e.png)
=
![√((-3)^2+(-6)^2)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/1tw0yuqlni8spmnlrw4ueu167iykpxwlx8.png)
=
![√(9+36)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/6jor1vj9e2fa9w920m1ldohgmstqs4n4tk.png)
=
![√(45)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/wrs17k349zw5fwdko9rjegmuwe2xebzj9u.png)
=6.70820393