scl rlr s tl fr msrng lngths nd trnsfrrng msrmnts t fxd rt f lngth; tw cmmn xmpls r n rchtct's scl nd ngnr's scl. n scntfc nd ngnrng trmnlgy, dvc t msr lnr dstnc nd crt prprtnl lnr msrmnts s clld scl. dvc fr drwng strght lns s strght dg r rlr. n cmmn sg, bth r rfrrd t s rlr.