The operations property states that

The Commutative Property of Addition states that changing the order of addends does not change the sum. The commutative property of multiplication states that two numbers can be multiplied in either order. The associative property states that you can add any numbers regardless of how the numbers are grouped.

Step-by-step explanation: This may be what you are talking about

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.