Find the measure of angle number 6.
o
50
5.5-6
Investigate Parallelogram
 Using the lines on a piece of line paper as a guide, draw
a pair of parallel lines that are at least 6 cm apart.
Using the parallel edges of your double-edged
straightedge, make a parallelogram. Label your
parallelogram LOVE.
•Let’s look at the opposite angles. Measure the angles
of parallelogram LOVE. Compare a pair of opposite
angles using patty paper or your protractor.
What did you notice?
 Find the sum of the measures of each pair of
consecutive angles in parallelogram LOVE.
 Let’s look at the opposite sides of parallelogram LOVE.
Compare the lengths of the opposite sides of the
parallelogram you made.
 Finally, let’s consider the diagonals of the
parallelogram. Construct the diagonals LV and EO.
Label the point where the two diagonals intersect
point M. Measure LM and VM. What can you
conclude about point M? Is this conclusion also true
for diagonal EO? How do they relate?
 The opposite angles of a parallelogram are
congruent
_____________.
 The consecutive angles of a parallelogram
supplementary
are _____________.
 The opposite sides of a parallelogram are
parallel and congruent
______________.
 The diagonals of a parallelogram
bisect each other
_________________.
Find the slope of: (4,6) and (-1, 9)
96
m
1  4
69
m
4  (1)
3
m
5
3
m
5
Be sure to have:
 scissors
 protractor
 ruler
We will investigate rhombus, square,
rectangle and kite.
Rhombus – equilateral parallelogram
congruent
 All 4 sides are _______________.
perpendicular and
 The diagonals are ______________,
they bisect
________________________.
each other
bisect
 The diagonals of a rhombus _____________
the angles of the rhombus.
Rectangle – parallelogram with 4
right angles
 The diagonals of a rectangle are
bisect each other
congruent
________________
and ___________________.
Square – parallelogram with 4 right
angles and 4 congruent sides
congruent
 The diagonals of a square are ________________,
________________
perpendicular and ___________________.
bisect each other
Kite – two pairs of consecutive
congruent sides
 The diagonals are ____________________.
perpendicular
opposite
 Exactly one pair of ________________
angles
congruent
are __________________.