Question

If m∠A = m∠B and m∠A + m∠C = m∠D, then
m∠B + m∠C = m∠D.

Which property is shown?

reflexive property
substitution property
symmetric property
transitive property

Answer 1

Substitution property.

Reason: Because m∠A = m∠B, you replace m∠A with m∠B in the equation m∠A + m∠C = m∠D to get m∠B + m∠C = m∠D.