A regular tape measure is a reliable assistant at short distances: the coil length is usually 2.5–5 meters. And to measure a segment of just a couple of meters, you will need the help of a second person.
But a laser rangefinder “shoots” as much as 1,500 meters. The error depends on the model, but on average does not exceed only 1.5–3 mm. And even this deviation can be reduced if you buy a model with an optical sight or put the rangefinder on a tripod.
In addition, unlike a tape measure, which allows you to set the length of only one segment at a time, you can set up to four reference points on the rangefinder. This will allow you to simultaneously measure different distances along one line. And thanks to the built-in calculator, you can forget about calculating the area “on paper”.