Question

what is the missing reason in step 3? statements reasons 1. (mangle trv = 60^{circ},mangle trs=(4x)^{circ}) 1. given 2. (angle trs) and (angle trv) are a linear pair 2. definition of linear pair 3. (mangle trs + mangle trv=180) 3. ? 4. (60 + 4x=180) 4. substitution property of equality 5. (4x = 120) 5. subtraction property of equality 6. (x = 30) 6. division property of equality substitution property of equality angle addition postulate subtraction property of equality addition property of equality

Explanation:

The angle - addition postulate states that if two angles form a linear pair, the sum of their measures is 180 degrees. Since ∠TRS and ∠TRV are a linear pair (from step 2), we use the angle - addition postulate to get m∠TRS + m∠TRV=180.

Answer:

angle addition postulate