Parallelograms – Properties   A parallelogram is a special type of a polygon. it is a quadrilateral with both pair of opposite sides are parallel. Properties 1. Opposite sides are equal.       Opposite sides, AB = CD and AC = BD 2. Opposite angles are equal.      Opposite angles are ∠A = ∠D and ∠B […]

Read More →

Polygons – Classification We classify polygons to the number of side orvertices based they have. A polygon can be classified by it’s number of a sides and measure of angles. First, we classify by it’s number of a sides.               Classified by measuring the sides The name of a polygon usually […]

Read More →

 Rhombus – Definition – Properties Definition: A rhombus is a quadrilateral (closed shape, plane figure) with four straight sides that are equal length also opposite sides are parallel and opposite angles are equal. A rhombuses is a type of parallelogram. All rhombuses are parallelograms, but not all parallelograms are rhombuses.  All squares are rhombuses, but not all […]

Read More →

Concave Polygons: Definition – Examples & Properties   All polygons is either convex or concave. A polygon will be convex or concave, it depends on the measure of their angles. What is a Concave Polygon? A concave polygon have at least four sides, and concave polygon is just opposite of a convex polygon. If the measures […]

Read More →

  Diagonals of Polygon’s In geometry, a line segment joining two vertices of a polygon or polyhedron, when those vertices are not adjacent is known as Diagonal.  Diagonals of Polygon’s A polygon’s diagonal’s are line segments, that joining from one corner to another corner. Formula for number of diagonals = n(n-3)/2 where n is number of sides or […]

Read More →

Definition, Properties, Examples – Cyclic Quadrilaterals What is a Cyclic Quadrilateral A cyclic quadrilateral is a four sided polygon that is inscribed in a circle. The vertices are said concyclic. The center of the circle is called circumcenter and radius of the circle is called circumradius. Definition: A Cyclic Quadrilateral is a quadrilateral, whose all four vertices […]

Read More →

Parallelograms on the same base and between the same parallels are equal in area. Given: Two parallelograms ABCD and EFCD, are on the same base DC and between the same parallel lines AF and DC. To prove: area (∥gm ABCD) = area (∥gm EFCD) Proof: In △ AED and △ BFC BC ∥ AD and AF is a transversal.So, ∠DAE = ∠CBF …..(1) (Corresponding angles of […]

Read More →

If each pair of opposite sides of a quadrilateral is equal, then it is a parallelogram.  Given: ABCD is a quadrilateral, each pair of opposite sides of quadrilateral ABCD are AB and CD and also sides AD and BC are equal. AB = CD BC = AD To prove: ABCD is a parallelogram. Construction: Join A to C that is AC, is […]

Read More →

Quadrilateral – Definition – Properties There are kinds of quadrilaterals, based on the sides and angles.  1. Parallelogram 2  Rectangle 3. Square 4. Rhombus 5. Trapezium 6. kite 1.                       Parallelogram A Parallelogram is a quadrilateral, whose both pairs of opposite sides are parallel and equal in length. In above […]

Read More →

Quadrilaterals – Definition – Properties The word “quadrilateral” has two Latin words quadri, a variant of four and latus meaning is “side”.                    What is a quadrilateral A quadrilateral is a polygon, with four edges or sides and four vertex or corners. Just like as a triangle is 3 sides polygon, […]

Read More →