Congruent segments

The topic  appears under the 7th Grade Math Mission. This exercise measures lengths on a number line and determines if segments are congruent.

Types of Problems
There is one type of problem in this exercise:


 * 1) Tell whether the segments are congruent: This problem has a number line with four labeled points. The student is asked to determine whether the segments AB and CD are congruent.Cs1-too.png

Strategies
Knowledge of absolute value representing length reinforces the idea of this problem, but is not necessary to complete it. Visual reasoning can increase efficiency.
 * 1) The length of a segment is the absolute value of the difference of it's endpoints.
 * 2) Two segments are congruent if they have the same length.
 * 3) The segments AB and CD do not overlap, so there is no need to worry about "cancelled" out length.
 * 4) Observation can sometimes determine if the segments are congruent or not without any calculation.