Triangles: Definition, Properties, Types, Area, Perimeter, Examples

Triangle has been used since long time ago in human life. There are many things in daily life that has triangle in shape for example ruler, hanger, slice of sandwich, front and back side of tent, surface of pyramid, etc.. Definition of Triangles Triangles is a two-dimension shape that bordered by three sides so that

Corresponding Angles: Theorem & Examples

Angle is formed by two rays that have a common end point. There are some types of angle. Here they are. Type of Angle In general, there are some kinds of angles: 1. Acute angle (less than 90°) Learn more about acute angle. 2. Right angle (90°) 3. Obtuse angle (more than 90° but less than

Reflex Angle

A Reflex Angle is more than 180° but less than 360° More Examples of Reflex Angle Which Angle? Remember to look carefully at which angle you are being asked to name. The reflex angle is the larger angle. It is more than 180° but less than 360° If you choose the smaller angle you might


Geometry is a branch of mathematics concerned with questions of shape, size, relative position of figures, & the properties of space. A mathematician who works in the field of geometry is called a geometer. There are some general concepts that are more or less fundamental to geometry. These include the concepts of points, lines, planes,

Exterior Angle Theorem

Exterior Angle Theorem For a triangle The exterior angle d equals the angles b plus c. (d = b + c) The exterior angle d is greater than angle b and angle c. (do > bo, do > co) Proof d = b + c : a + b + c = 180° (Because the interior angles of

Irregular Polygon

Regular polygon is a polygon that has all angles equal and all sides equal. So, regular polygon has a = b = c = d = e, and ∠v = ∠w =∠x = ∠y = ∠z Definition of Irregular Polygon Irregular polygon is a polygon that does not have all sides equal and all angles

Angles of Elevation & Depression

Angles of Elevation Angle of elevation is the angle from the horizontal upward to an object. An observer’s line of sight would be above horizontal line. The angle of elevation is angle formed by a horizontal line & line of sight up to an object when the object is above the line. When you see


Definition Translation means Moving without rotating, resizing or anything else, just moving. To Translate a shape Every point of the shape must move: the same distance in the same direction. Learn More Angles Acute Angles Obtuse Angles Supplementary Angles Geometry Index

Acute Angles

An Acute Angle is less than 90° More Examples of Acute angles Which Angle? Remember to look carefully at which angle you are being asked to name. The acute angle is the small angle which is less than 90°. The larger angle you will have a Reflex Angle (more than 180° but less than 360°)

Parallelogram: Definition, Area, Perimeter, Diagonal, Types, Examples

Definition of Parallelogram Parallelogram is a two-dimensional shape that has parallel sides each other. The parallel sides are equals in length. Parallelogram is also a quadrilateral because it has four sides. The angles are same in the opposite. The sum of adjacent angles is 180° (supplementary angles). Sum of α + β = 180° Area of a Parallelogram