Quadrilaterals and Their Properties

These flashcards cover key vocabulary and definitions related to the properties and types of quadrilaterals as discussed in the lecture notes.

Parallelogram

A quadrilateral having both pairs of opposite sides parallel.

Rhombus

A parallelogram with all sides equal in length.

Rectangle

A parallelogram with all angles being right angles.

Square

A quadrilateral where all angles are right angles and all sides are equal.

Trapezium

A quadrilateral with only one pair of opposite sides parallel.

Diagonal

A line segment that connects two non-adjacent vertices of a polygon.

Congruent

Having the same size and shape; in geometry, it refers to figures that can be made to coincide by rigid motions.

Adjacent angles

Two angles that share a common side and vertex.

Supplementary angles

Two angles whose measures add up to 180 degrees.

Proof

A logical argument that establishes the truth of a theorem or proposition in geometry.

Midpoint theorem

A line segment connecting the midpoints of two sides of a triangle is parallel to the third side and half its length.

Test for parallelogram

Criteria that can be used to determine if a quadrilateral is a parallelogram, such as opposite sides being congruent or angles being congruent.

Opposite angles

Angles that are across from each other in a polygon.

Bisect

To divide something into two equal parts.

Activity

An exercise used to help students understand geometrical properties and theorems.

Congruent triangles

Triangles that are identical in shape and size.