What is Geometry? – Geometry Definition, Formulas and Shapes

Geometry plays a crucial role not only in our daily lives but also in various competitive examinations. Question from this topic is asked in various government job recruitment tests, including those conducted by SSC, Railways, Defence, and numerous state-level examinations. Recognizing the importance of this topic for aspiring government job seekers, we are providing comprehensive study notes on Geometry. In the article below, we provide detailed information about geometric concepts, shapes, and formulas.

Geometry Definition

Geometry word is derived from Ancient Greek words – ‘Geo’ means ‘Earth’ and ‘metry’ means ‘measurement’. It can also be traced back to the Sanskrit word ‘Jyamiti’. Geometry is concerned with properties of space that are related to distance, shape, size, and relative position of figures. The basics of geometry depend majorly on points, lines, angles, and planes.

What are the Branches of Geometry?

There are various uses of  Geometry in daily life. It ranges from choosing the right size of any item to planning highly sophisticated space missions. Depending upon these applications, geometry can be classified in various branches. The branches of geometry are as follows:

• Algebraic geometry
• Discrete geometry
• Differential geometry
• Euclidean geometry
• Coordinate geometry
• Convex geometry
• Topology

Plane Geometry (2D Geometry)

Plane Geometry means flat shapes that can be drawn on a piece of paper. These include lines, circles & triangles of two dimensions. Plane geometry is also known as two-dimensional geometry which utilizes two coordinates in any space i.e. X and Y axis. Examples of 2D Geometry is square, triangle, rectangle, circle, lines, etc. Here we are providing you with the properties of the 2D shapes below.

Point

A point is a location or place on a plane. A dot usually represents them. It is important to understand that a point is not a thing, but a place. The point has no dimension and it has the only position. This position is also known as coordinates.

Line

The line is straight with no curves), has no thickness, and extends in both directions without end infinitely. It can be seen as a collection of points adjacent to each other. Almost all the shapes in geometry make use of lines and points. For example, shapes such as angles, triangles, rectangles, pentagons, and so on are made up using a collection of lines joined with each other.

Angles in Geometry

Angles are formed by the intersection of two lines called rays at the same point. which is called the vertex of the angle. It is utilized in the formation of a triangle, rectangle or more complex figures. These angles are of various types such as acute, right, obtuse and reflex. In the next section let us look at these in detail.

Types of Angle

1. Acute Angle – An Acute angle is an angle smaller than a right angle ie. it can be from 0 – 90 degrees.
2. Obtuse Angle – An Obtuse angle is more than 90 degrees but is less than 180 degrees.
3. Right Angle – An angle of 90 degrees.
4. Straight Angle – An angle of 180 degrees is a straight angle, i.e. the angle formed by a straight line.
5. Reflex Angle – These angles are greater than 180 degrees but less than 360 degrees.

Polygons