Answer:
70 yd.
Step-by-step explanation:
The three streets at the intersection form a right triangle.
For a right triangle, the length of the longest side (called hypothenuse) is given by Pythagorean's theorem:
where
x is the length of the 1st side
y is the length of the 2nd side
h is the length of the hypothenuse
Here we want to find the hypothenuse.
We have:
x = 42 yd (length of the 1st side)
y = 56 yd (length of the 2nd side)
Substituting, we find h: