Given that m∠ECG = 121°.
1. m∠FAC + m∠ECA = 180, they are supplementary angles
2. m∠FAC is also 121° because m∠ECG and m∠FAC are corresponding angles.
Thus, the correct choice is:
b- 1. Definition of Supplementary Angles; 2. Corresponding Angles Theorem
1. Supplementary angles are angles whose sum is 180°.
Since m∠FAC + m∠ECA = 180, they are supplementary angles.
2. Corresponding angles theorem:
Given that two lines are cut by a transversal, the corresponding angles will be congurent.
Since m∠FAC = m∠ECG, they are corresponding angles.
ANSWER:
b- 1. Definition of Supplementary Angles; 2. Corresponding Angles Theorem
