Say about the angles? D'
DO THIS
O
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

Aprofessional hockey team has noticed that, over the past several seasons, as the number of wins increases, the total number of hot dogs sold at the concession stands increases. the hockey team concludes that winning makes people crave hot dogs. what is wrong with the hockey team's conclusion? a) it does not take into account the attendance during each season. b) it does not take into account the number of hamburgers sold during each season. c) it does not take into account the number of concession stands in the hockey arena. d) it does not take into account the number of seasons the hockey team has been in existence.