長さ and 距離: an object's length and separation between points
Distinguish the length of an object from the distance between an origin and a destination.
An object's length
長さ, read ながさ, means length. ひもの長さを測りました。 means measuring the length of a string.
長さを半分にしました。 means reducing the length to half. An actual measurement requires knowing the original length.
Distance between points
距離, read きょり, means distance. 家から駅までの距離は二キロです。 says that the distance from home to the station is two kilometers.
二人の距離が近づきました。 says that the distance between two people became smaller. Context determines whether this is physical separation or closeness in their relationship.
Routes and measurements
道の長さ and 駅までの距離 show that length and distance can overlap in measurement contexts. First identify what is being measured or which two points are involved.
駅までの距離は分かりますが、所要時間は分かりません。 says that the distance to the station is known, but the travel time is not. Distance alone does not establish travel time.
Does 家から駅までの距離は二キロです mean the journey takes two minutes?
Show the answer and why
No. It gives a distance of two kilometers, not a duration.