# Geometry

A mindmap of geometry

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Geometry

## 1. Zero Dimentions

### 1.1. Points

1.1.1. No dimensions, only position

## 2. One Dimension

### 2.1. Lines

2.1.1. Infinitely long, no width

### 2.2. Line segments

2.2.1. Have finite length, but no width

## 3. Two Dimensions

### 3.1. Polygons

3.1.1. Plane figure that is described by a finite number of straight line segments connected

3.1.1.1. have 3 or more sides

3.1.1.2. regular polygons: all sides are equal

3.1.1.2.1. Interior angles in a regular polygon: ((Number of angles)-2)*180

3.1.2. Triangles

3.1.2.1. Pythagoream theorem

3.1.2.2. Congruence of triangles

3.1.2.3. Trignometry

3.1.2.4. Triangles can be similar and not congruent, sometimes- when their angles are the same length but their sides are not.

3.1.4. Circles

3.1.4.1. Polygons with infinite sides

### 3.2. Area calculations

3.2.1. Square: (side length)^2

3.2.2. Rectangle: side1*side2

3.2.3. Triangle: (0.5)(base length)(height)

### 3.3. Perimeter calculations

3.3.1. Square: 4*side length

3.3.2. Rectangle= 2(side1+side2)

### 3.4. Transversals

3.4.1. Equivalence of vertically opposite angles

3.4.2. Equivalence of corresponding angles

3.4.3. Equivalence of interior and exterior alternate angles

## 4. Three Dimensions

### 4.1. Solid geometry

4.1.1. Surface area calculations

4.1.2. Volume calculations

4.2.1. Cubes

4.2.2. Cuboids

4.2.3. Cones

4.2.4. Spheres