Geometry Basics

A point is a location in space, represented by a set of coordinates (x, y, z)
A line is a set of points extending infinitely in two directions
A plane is a flat surface that extends infinitely in all directions

An angle is formed by two rays sharing a common endpoint (vertex)
Types of angles:
- Acute angle: less than 90°
- Right angle: exactly 90°
- Obtuse angle: greater than 90° but less than 180°
- Straight angle: exactly 180°
Measurements:
- Degree: a unit of angle measurement (1° = 1/360 of a circle)
- Radians: a unit of angle measurement (1 radian = 180° / π)

Properties of triangles:
- Angles: sum of interior angles = 180°
- Sides: sum of any two sides > third side
Properties of quadrilaterals:
- Rectangles: all angles are right angles
- Squares: all sides are equal, all angles are right angles
Properties of circles:
- Center: fixed point equidistant from all points on the circle
- Radius: distance from center to any point on the circle
- Circumference: distance around the circle (2πr)

Types of 3D shapes:
- Pyramids: triangular base, triangular sides
- Prisms: rectangular base, rectangular sides
- Spheres: set of points equidistant from a central point
Properties of 3D shapes:
- Surface area: sum of areas of all faces
- Volume: amount of space inside the shape

An angle is formed by two rays sharing a common endpoint (vertex)
Angles can be classified into:
- Acute angles (less than 90°)
- Right angles (exactly 90°)
- Obtuse angles (greater than 90° but less than 180°)
- Straight angles (exactly 180°)

Triangles:
- The sum of interior angles is 180°
- The sum of any two sides is greater than the third side
Quadrilaterals:
- Rectangles have all angles as right angles
- Squares have all sides equal and all angles as right angles
Circles:
- The center is a fixed point equidistant from all points on the circle
- The radius is the distance from the center to any point on the circle
- The circumference is the distance around the circle (2πr)

Types of 3D shapes include:
- Pyramids (triangular base, triangular sides)
- Prisms (rectangular base, rectangular sides)
- Spheres (set of points equidistant from a central point)
Properties of 3D shapes include:
- Surface area is the sum of areas of all faces
- Volume is the amount of space inside the shape

Hindi uses the Devanagari script, written from left to right.
The script consists of 47 characters: 14 vowels, 32 consonants, and 1 special character (avagraha).

Hindi nouns are classified into three categories: masculine, feminine, and neuter.
Nouns have two numbers: singular and plural.
Case endings are used to indicate grammatical function, including:
- Nominative (subject)
- Accusative (direct object)
- Genitive (possessor or attribute)
- Dative (indirect object)
- Ablative (means or instrument)
- Locative (location)

Hindi verbs are inflected for:
- Tense: present, past, and future
- Aspect: simple, progressive, and perfect
- Mood: indicative, imperative, and subjunctive
- Voice: active and passive

Hindi postpositions are used to indicate grammatical relationships between nouns and other words.
Common postpositions include:
- के (ke)
- से (se)
- में (meṁ)
- पर (par)

Hindi has a system of honorifics to show respect or politeness.
Honorifics are used with verbs, nouns, and pronouns to indicate respect or deference.
The use of honorifics depends on the speaker's relationship with the listener or subject.