## Presentation on theme: "Special Quadrilaterals"— Presentation transcript:

Honors Geometry

True/False Every square is a rhombus.

TRUE – four congruent sides

True/False If the diagonals of a quadrilateral are perpendicular, then it is a rhombus.

False – diagonals don’t have to be congruent or bisect each other.

True/False The diagonals of a rectangle bisect its angles.

FALSE (draw an EXTREME rectangle!)

True/False A kite with all consecutive angles congruent must be a square.

TRUE

True/False Diagonals of trapezoids are congruent.

FALSE – not always!

A parallelogram with congruent diagonals must be a rectangle.
True/False A parallelogram with congruent diagonals must be a rectangle.

TRUE

True/False Some rhombuses are rectangles.

True – some rhombuses also have right angles

True/False The diagonals of a rhombus are congruent.

False – not always!

True/False If the diagonals of a parallelogram are perpendicular, it must be a rhombus.

TRUE

True/False Diagonals of a parallelogram bisect the angles.

FALSE

True/False A quadrilateral that has diagonals that bisect and are perpendicular must be a square.

FALSE (could be rhombus… right angles not guaranteed)

Sometimes/Always/Never
A kite with congruent diagonals is a square.

FALSE – could be, but diagonals don’t have to bisect each other.

Give the most descriptive name:
A parallelogram with a right angle must be what kind of shape?

Rectangle

Give the most descriptive name:
A rectangle with perpendicular diagonals must be what kind of shape?

SQUARE

Give the most descriptive name
A rhombus with consecutive angles congruent must be a:

SQUARE

Give the most descriptive name:
A parallelogram with diagonals that bisect its angles must be a:

Rhombus

Proving that a Quad is a Rectangle
If a parallelogram contains at least one right angle, then it is a rectangle. If the diagonals of a parallelogram are congruent, then the parallelogram is a rectangle. If all four angles of a quadrilateral are right angles, then it is a rectangle.

Proving that a Quad is a Kite
If two disjoint pairs of consecutive sides of a quadrilateral are congruent, then it is a kite. If one of the diagonals of a quadrilateral is the perpendicular bisector of the other diagonal, then it is a kite.

Proving that a Quad is a Rhombus
If a parallelogram contains a pair of consecutive sides that are congruent, then it is a rhombus. If either diagonal of a parallelogram bisects two angles of the parallelogram, then it is a rhombus. If the diagonals of a quadrilateral are perpendicular bisectors of each other, then the quadrilateral is a rhombus.

Proving that a Quad is a Square
If a quadrilateral is both a rectangle and a rhombus, then it is a square.

Proving that a Trapezoid is Isosceles
If the non-parallel sides of a trapezoid are congruent, then it is isosceles. If the lower or upper base angles of a trapezoid are congruent, then it is isosceles. If the diagonals of a trapezoid are congruent, then it is isosceles.