Step-by-step explanation:
Statements Reasons
1 . ∠ABC and ∠CBD are a linear pair Given
2. m∠CBD = m∠EFG Given
3 . ∠ABC and ∠CBD are supplementary Definition of linear pair
4. m∠ABC + m∠CBD = 180° Definition of supplementary
5. m∠ABC + m∠EFG = 180° Substitution property
6. ∠ABC and ∠CBD are supplementary Definition of supplementary