Triangle
Area of the triangle =
x base x height.
Quadrilateral
To find the area of a quadrilateral divide the quadrilateral into two triangles and add the areas of the two triangles. The method of dividing a quadrilateral into two triangles to find out its area is known as triangulation.
Let ABCD is a quadrilateral.
Then Area of quadrilateral ABCD = (Area of ∆ ABD) + (Area of ∆ BCD)
Area of quadrilateral ABCD =
d (h
1 + h
2), where d is the diagonal and h
1 and h
2 are the heights of the quadrilateral.
Square
Area of the square = a
2 , where a be the length of each side of a square.
Perimeter of square = 4a.
Diagonal of a square = √2a
Rectangle
Area = length x breadth
Perimeter = 2( length + breadth)
Diagonal =
, where l = length b = breadth.
Parallelogram
In a parallelogram the diagonal divide it into two triangles.
Area of a Parallelogram = base × height
Perimeter = 2( Sum of two adjacent sides)
Rhombus
In a rhombus diagonals are perpendicular to each other, so we can use the method of triangulation to find the area of a rhombus.
Area of a Rhombus =
(d
1 x d
2), where d
1 and d
2 are the lengths of the diagonals.
Side of the rhombus =
Perimeter = 4 x (Side) = 2
Area of rhombus DEFG = (½ x EO x DF) + (½ x GO x DF)
= ½ x DF x (DF + GO)
= ½ x DF x GE
= ½ x d
1 x d
2
Trapezium
A trapezium has a pair of parallel sides.
Area of trapezium = h
Where h = perpendicular distance between the parallel sides of a trapezium and a and b are the lengths of the parallel sides.
A polygon is a closed shape that has at least three sides. It is a closed shape that has at least three sides. Triangles, quadrilaterals, rectangles and squares are all types of polygons. Moreover, a polygon can be of any shape and can have any number of sides. There is no specific formula for calculating the area of a polygon. The best way is to split the polygon into shapes whose area can be calculated individually.
