what is the meaning of closing error?

what is the meaning of closing error?

the question is related with the different laws of forces for example triangle law, polygon law.

(general) The amount by which a quantity obtained by a series of related measurements differs from the true or fixed value of the same quantity. Also called closing error; closure. 2. (angles) The amount by which the actual sum of a series of angles fails to equal the theoretically exact value of that sum. Also called angular error of closure. 3. (azimuth) The amount by which two values of the azimuth of a line, derived by different surveys or along different routes, fail to be exactly equal to each other. Also called azimuth error of closure. 4. (leveling) The amount by which two values of the elevation of the same bench mark, derived by different surveys or through different survey routes or by independent observations, fail to be exactly equal to each other. Also called leveling error of closure. See also circuit closure. 5. (loop) The error in the closure of a survey on itself. Loops do not protect against systematic errors in distance measurement or blunders in starting position o