Answer:
1. false
2. true
3. true
Step-by-step explanation:
1. Since a and b are right angles, a+b = 180, not 90, false
2. since a right angle is 90 degrees and b is a right angle, 90 + 90 = 180 true
3. B and A are right angles, so 180 - 90 = 90 true
Hope this is helpful:)
