Question

tell me the formulas related to understanding quadrilaterals

Answer 1

hey there
you can see your text book there are many formulas related to understanding quadrilaterals
i hope this may help you

Answer 2

let ABCD is a quadrilateral.

Then Area of quadrilateral ABCD = (Area of ∆ ABD) + (Area of ∆ BCD)

1.       Area of quadrilateral ABCD =  1 2 d (h1 + h2), where d is the diagonal and h1 and h2 are the heights of the quadrilateral.


square:

Area of the square = a2 , 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 = l 2 + b 2  , 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

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 d1 x d2