# Areas in Geometry

### Area of a Square

### A = x^{2}

where: A is the area and x is the side of the square

### Area of a Rectangle

### A = xy

where: x and y are the adjacent sides of the rectangle

### Area of a Circle

### A = Πr^{2}

where: **r** is the radius of the circle and **Π = 3.14**

### Area of a Triangle

There are three formulas:

#### First

where: **b** is the base of the triangle and **h**
is the height which the perpendicular distance from the
vertex to the base

#### Second

">

where: **a** and **b** are two sides and **C** is the angle opposite to the third side c.

#### Third

Where **a, b** and **c** are the three sides
of the triangle

and

or half the perimeter

### Area of Trapezium

### A = [(x+y)/2]h

where: **x** and **y** are the two parallel
sides and **h** is the perpendicular distance between the
parallel sides

### Area of a Parellelogram

### A = b x h

where: **b** is the base and **h** is the
perpendicular distance of the opposite side from the base