if a = 90 - 23, then a = 67

Start from the conclusion and work back up the proof. Click the arrow to show the parents.

• a = 67,

  if the following are true:

  • a = b
  • b = c

  then a = c

  • 90 - 23 = 67, 90 - 23 = 67
  • a = 90 - 23