How do we use geometry in real life?

How do we use distance formula of coordinate geometry in real life situations ?

• In real life situations how do we use formulae of coordinate geometry ? i need to teach this to class 9 students in school.

• Answer:

  Surveying uses distance formulas and trigonometry. There are three major trig functions, and they are fractions, often of lengths. sine = Oscar had = opposite/hypotenuse cosine = a handful = adjacent/hypotenuse tangent = of apples = opposite/adjacent The hypotenuse is the side opposite the 90 degree angle in a right triangle. The opposite is the side opposite one of the 2 smaller angles. The adjacent is the side next to one of the smaller angles. The functions are of that particular angle. Trig and distance formulas were of supreme importance to seamen before the invention of the modern clock ("Longitude", by Dava Sobel) because they plotted their course by "dead reckoning", the only method they had, and young officers (teenage) in the British Navy had mandatory daily maths lessons, so that they would not end up crashing on a reef. They used hour glasses for time.