1. Quadrilaterals In Flags
Heyam Ibrahim Aljneibi
Meitha suroor Almentheri
9-asp1

2. A quadrilateral is a shape with four sides and four corners
A quadrilateral is a shape with four sides and four corners. Sometimes, they are called quadrangles or tetragons. The word quadrilateral is made of the words quad (meaning "four") and lateral (meaning "of sides").

4. Opposite sides are equal in length.
Uae
Rectangle
Opposite sides are equal in length.

6. Philippines
Trapezoid
Bases are parallel

8. Chile
Square
All equal sides

10. Diagonals are perpendicular
Rhombus
Diagonals are perpendicular

11. Formulas Square(Area = a2) Trapezoid(Area = ½(a+b) × h)
Rectangle(Area = w × h)
Rhombus(Area=pq/2)

12. Non-quadrilateral flag Nepal's flag
Nepal's flag is the only flag in the world that is not quadrilateral.
Nepal's shape is very unique
It is basically two triangles combined.