Answer:
The answer is "3 km ".
Step-by-step explanation:
Distance in (km): 
Elevation value in (m): 

The graph intersects the x-axis twice. It intersects at the points of (-1,0) and (2.5,0). The graph is attached.
The angles in a isosceles triangle add up to 180 degrees.
so 180 degrees take away 36 degrees = 144 degrees.
base angles in a isoceles triangle are equal so 144 divided by 2 = 72 degrees.
so to find out y you do 360 - 72 = 288 degrees
therefore y = 288degrees
I would say the answer is 35.