Final answer:
By subtracting m∠B from both sides of the equation m∠A + m∠B = m∠B + m∠C, we use properties of equality to show that m∠C = m∠A.
Step-by-step explanation:
The problem m∠A + m∠B = m∠B + m∠C is a mathematical statement that requires us to show that m∠C = m∠A. This can be proved using properties of equality. Since m∠A + m∠B equals m∠B + m∠C, by the Subtraction Property of Equality, we can subtract m∠B from both sides, which leads us to m∠A = m∠C. This is a direct result of the Commutative Property of Addition and the Subtraction Property of Equality that demonstrates the two angles have the same measure.