Final answer:
The Transitive Property of Congruence, Symmetric Property of Congruence, Substitution Property, and Multiplication Property of Equality are the properties that justify the given statements in mathematical reasoning.
Step-by-step explanation:
The properties that justify the given mathematical statements are:
- If angle 1 is congruent to angle 2 and angle 2 is congruent with angle 3, then angle 1 is congruent with angle 3. The property that justifies this statement is the Transitive Property of Congruence.
- If angle ABC is congruent to angle DEF, then angle DEF is congruent to ABC. This statement is justified by the Symmetric Property of Congruence.
- If 2x + y = 5 and x = y, then 2x + x = 5. The property used here is the Substitution Property, as x is substituted for y in the equation.
- If the measure of angle A = 15, then 3 times the measure of angle A = 45 degrees. This uses the Multiplication Property of Equality because you are multiplying both sides of an equation by the same number.