SOLUTION: Given: Parallelogram ABCD is inscribed in a circle Prove: ABCD is a rectangle I was thinking to start out saying that since parallelograms have congruent opposite sides, then t

Algebra ->  Geometry-proofs -> SOLUTION: Given: Parallelogram ABCD is inscribed in a circle Prove: ABCD is a rectangle I was thinking to start out saying that since parallelograms have congruent opposite sides, then t      Log On


   



Question 310458: Given: Parallelogram ABCD is inscribed in a circle
Prove: ABCD is a rectangle
I was thinking to start out saying that since parallelograms have congruent opposite sides, then the congruent chords would have congruent arcs, but then I got stuck. Could you please help me? I need this answer ASAP.

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Solution:
LBAC= LBCD( opposite angles of a parallelogram are equal)
.
LBAC + LBCD = 180° ( opp. angles of a cyclic quadrilateral are supplementary)
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LBAC=LBCD= 90°
.
Similarly LABC=LADC=90°
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ABCD is a rectangle ( all the angles are =90°)
L stands for angle