two-line angular size where the straight lines are associated with two extracted lines resulting from the intersection of two extracted surfaces with a plane perpendicular to their associated straight line of intersection, kahejoone nurkmõõde, kui sirgjooned on seotud kahe tuletatud joonega, mis tulenevad kahe tuletatud prismapinna ristumiskohast, mille tasapind on risti nendega seotud sirgjoonega