Explanation:
I assume they intersect at a right angle (90°).
then the intersection is a rectangle with one side being 12 m, and the diagonal being 13 m long.
the diagonal is the Hypotenuse (baseline) of a right-angled triangle with the length and the width of the rectangle as legs.
so, by using Pythagoras we have
diagonal² = length² + width²
13² = 12² + width²
169 = 144 + width²
25 = width²
width = 5 m
so, Oakdale Avenue is 5 m wide.