# Geometry

Geometry is a branch in mathematics which deals with all the shapes and their properties. It can be divided into two types:

- Plane Geometry.
- Solid Geometry.

## Plane Geometry

Plane geometry is all about flat shapes circles, lines, triangles etc. All the shapes that can be drawn on paper.

## Solid Geometry

Solid geometry deals with 3D (three dimensional) objects. For example: cube, prism, cylinder etc.

## What is a Point, Line and a Ray?

**Point:** It is defined as a particular or precise location on a piece of paper or a plane surface, represented by a dot.

**Line: **A line can be said a combination of infinite points together. It extends in both the directions.

**Ray: **When a line has starting point and no end point it is called as ray.

## Angle

Angle is a figure formed by two lines or rays, sharing a common end point (vertex).

**Types of angles:**

- Acute angle.
- Right angle.
- Obtuse angle.
- Straight angle.
- Reflex angle.
- Full angle.

### Acute Angle

Angle smaller than 90⁰ is called acute angle. It ranges from 0⁰ - 90⁰.

### Right Angle

An angle of 90⁰.

### Obtuse Angle

Angle greater than 90⁰ but lesser than 180⁰ is called an obtuse angle. It ranges from 90⁰ - 180⁰.

### Straight Angle

An angle of 180 is called straight angle. It is formed by a straight line.

### Reflex Angle

Angle greater than 180⁰ but lesser than 360⁰ is called a reflex angle.

### Full Angle

An angle which has an exact measure of 360⁰ is called full angle.