Which equations are true?

Choose all answers that are correct.



A.
m∠3 = m∠1 + m∠2

B.
m∠3 = m∠1 – m∠2

C.
m∠1 = m∠2 + m∠3

D.
m∠1 = m∠2 – m∠3

Please help and thank you