Transcript Quiz (8 points)

6-3 Ways to prove that
Quadrilaterals Are Parallelograms
Theorem
• If both pairs of opposite sides of a quadrilateral
are congruent, then the quadrilateral is a
parallelogram.
▫ This should make sense because we know from
Sec. 6.2 that in a parallelogram opposite sides are
congruent.
Prove previous theorem
T
S
3
G : TS  QR; TQ  SR
P : Quad QRST is a parallelogram
1
Q
2
4
R
Theorem
• If one pair of opposite sides of a quadrilateral
are both congruent and parallel, then the
quadrilateral is a parallelogram
Theorem
• If both pairs of opposite angles of a quadrilateral
are congruent, then the quadrilateral is a
parallelogram
Theorem
• If an angle is supplementary with both of its
consecutive angles then a quadrilateral is a
parallelogram.
Theorem
• If the diagonals of a quadrilateral bisect each
other, then the quadrilateral is a parallelogram.