Quadrilaterals and Their Properties

Vocabulary flashcards covering quadrilaterals, their properties, definitions, and special features based on the lecture notes.

Quadrilateral

A shape that has four sides and four angles.

Trapezium

An irregular quadrilateral with no parallel sides.

Trapezoid

A quadrilateral that has at least one pair of parallel sides.

Bases (of a Trapezoid)

The parallel sides (top and bottom) of a trapezoid.

Legs (of a Trapezoid)

The non-parallel sides (left and right sides) of a trapezoid.

Midsegment (of a Trapezoid)

A line segment that is parallel to the bases, with a length equal to the average of the two bases: $m = \frac{b_1 + b_2}{2}$.

Isosceles Trapezoid

A trapezoid in which the two legs are congruent and the base angles are congruent.

Kite

A quadrilateral with $2$ pairs of adjacent congruent sides (where adjacent sides share a vertex), one pair of congruent opposite angles, perpendicular diagonals (meeting at $90^\circ$), one bisected diagonal, and generally one line of symmetry.

Parallelogram

A quadrilateral with $2$ pairs of parallel sides, congruent opposite sides, congruent opposite angles, supplementary consecutive angles, and diagonals that bisect each other.

Rhombus

A parallelogram with congruent sides.

Rectangle

A parallelogram with right angles.

Square

A rectangle with $4$ equal sides.

Congruent

Matching or equal.

Adjacent

Beside each other; for sides, it means they share a vertex.

Bisect

To divide something into two equal parts.

Consecutive Angles

Two angles beside each other that share a side; in a parallelogram, consecutive angles are supplementary and add up to $180^\circ$.

Isosceles

A shape that has at least two equal sides.

Isosceles Triangle

A triangle with $2$ congruent (equal) sides, where the $2$ angles opposite those sides are also congruent.

Perpendicular

Two lines that meet at a $90^\circ$ angle.

Vertex

The corner of a shape.