1. 6.4 Rhombuses, Rectangles, and Squares 6.5 Trapezoids and Kites
Geometry
6.4 Rhombuses, Rectangles, and Squares
6.5 Trapezoids and Kites

2. Rhombus
A parallelogram with four congruent sides
Rectangle
A parallelogram with four right angles.
Square
A parallelogram with four congruent sides and four right angles.

3. Theorem
A parallelogram is a rhombus iff its diagonals are perpendicular.
A parallelogram is a rhombus iff each diagonal bisects a pair of opposite angles.
A parallelogram is a rectangle iff its diagonals are congruent.

4. Trapezoid
A quadrilateral with exactly one pair of parallel sides.
Isosceles Trapezoid
A trapezoid with congruent legs.

5. Theorem
If a trapezoid is isosceles, then each pair of base angles is congruent.
If a trapezoid has a pair of congruent base angles, then it is an isosceles trapezoid.
A trapezoid is isosceles iff its diagonals are congruent.

6. Midsegment
The midsegment of a trapezoid is the segment that connects the midpoints of its legs.
Midsegment Theorem for Trapezoids
The midsegment of a trapezoid is parallel to each base and its length is one half the sum of the lenghts of the bases.

7. Kite
A quadrilateral that has two pairs of consecutive congruent sides.
Theorem
If a quadrilateral is a kite, then its diagonals are perpendicular.
If a quadrilateral is a kite, then exactly one pair of opposite angles are congruent.