Supply the missing steps in the following paragraph proof.

Question

Given: ∠1 and ∠2 are supplementary, and ∠2 and ∠3 are supplementary
Prove: ∠1 ≈∠3

By the definition of supplementary angles, m∠1 + m∠2 = 180˚ and
m∠2 + m∠3 = 180˚. (did I get 180 right on these two)
Then, m∠1 + m∠2 = m∠2 + m∠3 by_______________.
Subtract m∠2 from each side. You get m∠1 = _____ or ∠1 ≈______.

I can't figure out the rest

Answer 1

HELPPP!!

Answer 2

i think i got it idk

Answer 3

Then, m∠1 + m∠2 = m∠2 + m∠3 by the substitution property.
Subtract m∠2 from each side. You get m∠1 m∠3 = or ∠1 ≈ m∠3.