Category: 02. Polygons

To help you see what the sum of all exterior angles of a polygon is, we will use a square and then a regular pentagon. Since it is very easy to see what the sum is for a square, we will start with the square. You can also use rectangles!    Notice that an exterior…

The properties of a parallelogram are listed below. We will use a parallelogram ABCD to show these properties. Property #1 Opposite sides of a parallelogram are congruent. The length of AB is equal to the length of DC.The length of BC is equal to the length of AD. Here is how to prove that opposite…

A parallelogram is a special quadrilateral with both pairs of opposite sides parallel as shown in the figure below. Notice that the opposite sides that are parallel lines are shown using the same amount of arrow heads. Types of parallelogram Squares, rectangles, and rhombuses are also parallelograms, more specifically special parallelograms, since their opposite sides…

The diagram below shows the relationships among special quadrilaterals. This diagram can help students answer tricky questions about quadrilaterals. Teachers, my personal recommendation is to use this diagram before going over definitions. Important observation Rectangles, rhombi, and squares are parallelograms. A square is a rectangle. A square is a rhombus. A rhombus is not a…

There are six types of quadrilaterals and these quadrilaterals can be classified by the relationships of their sides and angles. How to identify a parallelogram A parallelogram is a four-sided polygon with two pairs of parallel and equal sides. The following figure is a parallelogram. In a parallelogram, all the followings are true: How to…

The different types of triangles may be classified by their side lengths, by their internal angles or by a combination of both their side lengths and their internal angles. Basically, there are six types of triangles that can be classified either by their sides or by their angles. Types of triangles classified by their sides…

Concave polygons are polygons for which a line segment joining any two points in the interior does not lie completely within the figure. The word interior is important. You cannot choose one point inside and one point outside the figure. The following figure is concave: Segment AB does not entirely lie within the polygon. That is why the polygon…

Convex polygons are polygons for which a line segment joining any two points in the interior lies completely within the figure. The word interior is important. You cannot choose one point inside and one point outside the figure. The figure above with six sides meets this criteria and therefore is a convex polygon.No matter how I choose…

There are many different types of polygons. To explore them all along with their properties can be a course in itself. Basically, a polygon is a closed plane figure made of three or more sides. Number of sides Name of polygon 3 triangle 4 quadrilateral 5 pentagon 6 hexagon 7 heptagon 8 octagon 9 nonagon…