Conditions that Make a
Quadrilateral a
Parallelogram
Direction: Analyze the diagram below. What do you remember
about the family of quadrilaterals?
Can you define and illustrate the different kinds of quadrilaterals?
QUADRILATERAL
TRAPEZOID
PARALLELOGRAM
KITE
ISOSCELES
TRAPEZOID
RECTANGLE
RHOMBUS
SQUARE
QUADRILATERALS THAT ARE PARALLELOGRAMS
• A quadrilateral is a four-sided polygon. It has 4 vertices and the sum
of the interior angles is 360 degrees.
There are conditions that should be determined to prove that
quadrilaterals are parallelograms. These are the following:
1. In a parallelogram, any two opposite sides are congruent.
2. In a parallelogram, any two angles are congruent.
3. In a parallelogram, any two consecutive angles
are supplementary.
There are conditions that should be determined to prove that
quadrilaterals are parallelograms. These are the following:
4. The diagonals of a parallelogram bisect each other.
5. The diagonals of a parallelogram in two congruent triangles.
Practice!
Direction: Write TRUE if the statement is correct; otherwise,
write FALSE.
1. A quadrilateral is a parallelogram if both pairs of opposite sides are
congruent. TRUE
2. A quadrilateral is a parallelogram if both pairs of opposite sides are
supplementary.
FALSE
3. A quadrilateral is a parallelogram if any two consecutive angles are
complementary.
FALSE
4. A quadrilateral is a parallelogram if the diagonals bisect each other.
TRUE
5. A quadrilateral is a parallelogram if the diagonals form two congruent
triangles. TRUE
Keep Practicing!
Direction: Refer to the given figure at the
right and answer the following.
EY
∠Y
𝟏𝟖𝟎°
AX
△EAY
Seatwork 1
Direction: Refer to the given figure at the right and answer the following.
ASSIGNMENT: