SOLUTION: I have Everything made for my 2 column proof, the only thing I am having trouble with is what to write for my plan. Please help me with my plan! Given: PQ is a diameter of circl

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Question 604203: I have Everything made for my 2 column proof, the only thing I am having trouble with is what to write for my plan. Please help me with my plan!
Given: PQ is a diameter of circle O, AB is tangent to O at P, CD is tangent to O at Q
Prove: AB // CD
Plan: ??
Statements:
O is a circle (given)
PQ is a diameter of O (given)
AB tangent to O at P (given)
CD tangent to O at Q (given)
AB // CD (sum of interior angles is 180�)

Answer by scott8148(6628) (Show Source):
You can put this solution on YOUR website!
PQ is a transversal between AB and CD

AB and CD are parallel because the alternate interior angles formed by the transversal are equal

the angles are equal because tangent lines are perpendicular to the diameter at the point of tangency
___ perpendicular lines form equal right angles