# Area and Perimeter Formulas

### Triangle

Equilateral Triangle |
Isosceles Triangle |
Scalene Triangle |

### Square

### Rectangle

### Rhombus

### Rhomboid

P = 2 · (a + b)

A = b · h

### Area of Trapezoid

### Area of a Regular Polygon

n is the number of sides

### Polygon

The area is obtained by triangulating the polygon and adding the area of these triangles.

A = T_{1 } + T_{2 } + T_{3 } + T_{4 }

### Circle

### Circular Sector

### Circular Segment

The circular area of the segment AB = Area of the circular sector AOB - Area of triangle AOB

### Lune of Hippocrates

Area of the lune = area of the semicircle − area of circular segment.

### Circular Trapezoid

### Area enclosed between Two Concentric Circles

Subject

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