Answer:
In electronic devices like mobiles, laptops, computers, TVs, etc. In stationery items like books, copies, chart-papers, etc. The list goes countless as we can't imagine the world without quadrilaterals. Wherever you see four sides, quadrilateral is involved there. By above definition, square , rectangle, trapazoid, kite, rhombus, rhomboid, etc i.e every shape you can imagine with 4 sides is a quadrilaterals. Everything from blueprints (of homes) , doors, window, swimming pool, boxes, football ground, paper etc. is generally made up of such quadrilaterals.
