Proof: Supplementary Angles Theorem

Let's prove the following theorem:

if ∠ABX and ∠XBC are supplementary, then m∠ABC = 180

X A B C

Proof:

View as a tree | View dependent proofs | Try proving it

Given
1 ∠ABX and ∠XBC are supplementary
Proof Table
# Claim Reason
1 (m∠ABX) + (m∠XBC) = 180 if ∠ABX and ∠XBC are supplementary, then (m∠ABX) + (m∠XBC) = 180
2 m∠ABC = (m∠ABX) + (m∠XBC) if (m∠ABX) + (m∠XBC) = 180, then m∠ABC = (m∠ABX) + (m∠XBC)
3 m∠ABC = 180 if m∠ABC = (m∠ABX) + (m∠XBC) and (m∠ABX) + (m∠XBC) = 180, then m∠ABC = 180

Comments

Please log in to add comments