Say about the angles? D'
DO THIS
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A
Let ABCD be a parallelogram (Fig 3.23). Copy it on
a tracing sheet. Name this copy as A'B'C'D'. Place
A'B'C'D' on ABCD. Pin them together at the point
where the diagonals meet. Rotate the transparent sheet
by 180°. The parallelograms still concide; but you now
find A' lying exactly on C and vice-versa; similarly B'
lies on D and vice-versa.
В'
Fig 3.23
Does this tell you anything about the measures of the angles A and C? Exami
me for angles B and D. State your findings.
property: The opposite angles of a parallelogram are of equal measure.
TRY THESE