Name the below quadrilaterals.
Ext: Can you find another name?
Why is a parallelogram called a parallelogram?
What does parallel mean?
Two lines are called parallel if they never intersect.
Parallel lines
Not parallel lines
Draw two pairs of parallel lines such that
the lines of the second pair intersect the lines of
the first pair.
You will get a quadrilateral.
Draw a few more …
In each one measure the lengths of the sides.
What do you notice about the length of the
opposite sides?
A parallelogram is a quadrilateral with
two pairs of parallel sides
Reminder:
The diagonals of a square:
1) are of equal length
2) bisect each other (intersect at their
midpoints)
3) intersect at a right angle
The diagonals of a rectangle:
1) are of equal length
2) bisect each other (intersect at their
midpoints)
Let’s look at the diagonals of a parallelogram:
Draw different parallelograms in your books with diagonals
Measure along each diagonal the distance from each
vertex to the intersection point and the angle at which
the diagonals intersect.