Complex sentence: Knotted cords were used by rope stretchers or royal surveyors who measured out the sides of fields (Egyptian "3ht") using knotted cords (Egyptian "ht") of 100 royal cubits in length with a knot every "hayt" or 10 royal cubits.
Split into simpler sentences: Knotted cords were used by rope stretchers, royal surveyors who measured out the sides of fields (Egyptian "3ht"). The knotted cords (Egyptian "ht") were 100 royal cubits in length with a knot every "hayt" or 10 royal cubits.