He let you off easy! Could have given the geometry fromula to calculate total distance from elevatin gain and map distance.

In reality, our hiking paths are usually lower angle than the drawing. Even what we think is steep uphill is usually under 20 degrees, so the actual distance is not off as much as the drawing implies.

Off subject, but, I just discovered the "health" program on my I-phone (OK, I am late to figure this out). It gives steps and distances. I find this is quite a bit off at times. It seems to significantly over-estimate distance just puttering around, and slightly underestimate distance on a real long-stride walk. On one of my dog walks that I have determined as 4.5 miles on a real GPS, it gives me anywhere from 3.5 to 3.4 miles. I just got back from afternoon grocery shopping and it said 1.0 miles (no way!). Supposedly it uses a combination of steps and GPS tracking to get those numbers. Since I live in flat-land, the diagram above does not apply.