If a=(3,2) and b=(5,7) be two points , find the unit vector along ba

If we were to plot the points on a graph, we could draw a straight lint between them. The question wants us to find the length of this line. We could make a right triangle with this line as the hypotenuse, with an x length of 2(y2-y1) and a y length of 5 (y2-y1). From there we can find the hypotenuse with Pythagorean Theorem: c^2=a^2+b^2. 
c^2=(2)^2+(5)^2
c^2=4+25
C^2=41
c=
Decimal approximation: 6.403

Hope this helps!