Week 6 - Parallelogram

1. QUADRILATERAL
Lesson 6

2. • Any four-sided polygon is a quadrilateral.
• The sum of the interior angles is always 360°.

3. Parallelogram
LESSON 6
SLIDE
•Parallelogram
•Rectangle
•Square
•Rhombus
•Trapezoid
•Trapezium
•Isosceles Trapezoid
•Kite

4. Parallelogram
LESSON 6
SLIDE
A parallelogram
- is a quadrilateral whose opposite sides are parallel.
- Is a quadrilateral with two pairs of parallel sides.

5. Parallelogram
LESSON 6
SLIDE
• A parallelogram is named using all four vertices.
• You can start from any one vertex, but you must
continue in a clockwise or counterclockwise direction.
• For example, this can be either
ABCD or ADCB.
C
B
A D

6. Parallelogram
LESSON 6
SLIDE
• There are four basic properties of all parallelograms.
• These properties have to do with the angles, the sides
and the diagonals.

7. Parallelogram
LESSON 6
SLIDE
1. Sides
• If a quadrilateral is a
parallelogram, then its
opposite sides are congruent.
►PQ≅RS and SP≅QR
P
Q R
S

8. Parallelogram
LESSON 6
SLIDE
2. Angles
• If a quadrilateral is a
parallelogram, then its
opposite angles are congruent.
P ≅ R
and
Q ≅ S P
Q R
S

9. Parallelogram
LESSON 6
SLIDE
3. Consecutive Angles
• If a quadrilateral is a parallelogram,
then its consecutive angles are
supplementary (add up to 180°).
mP +mQ = 180°,
mQ +mR = 180°,
mR + mS = 180°,
mS + mP = 180°
P
Q R
S

10. Parallelogram
LESSON 6
SLIDE
4. Diagonals
• If a quadrilateral is a
parallelogram, then its
diagonals bisect each other.
QM ≅ SM
and
PM ≅ RM
Note: The diagonals are not congruent!
PR ≠ QS
P
Q R
S

11. SLIDE
References
E-Math 9 - Work Text in Mathematics (Rex Book Store)
Math Ideas and Life Applications 9 - Second Edition (Abiva)
Spiral Math 9 – (Trinitas Publishing Inc.)
Parallelogram
LESSON 6