Quadrilaterals (Jump to: Lecture | Video )

Quadrilaterals

A Quadrilateral is a closed figure with four sides, and four vertices.

Figure 1.

Above is quadrilateral ABCD.

All four angles in a quadrilateral sum to 360 degrees.

So, Angle A + Angle B + Angle C + Angle D = 360 degrees.

Specific names can be given to certain types of quadrilaterals. You're probably already familiar with some of them:

Parallelogram

In a parallelogram:

-all opposite sides are parallel

-all opposite sides are congruent

Trapezoid

In a trapezoid:

-one pair of opposite sides is parallel

Rectangle

In a rectangle:

-all opposite sides are parallel

-all opposite sides are congruent

-contains four right angles

Rhombus

In a rhombus:

-all opposite sides are parallel

-all sides are congruent


Back to Top