Engineers and architects use a lot of trigonometry for their designs. No buildings are built without the use of trigonometry to calculate angles and lengths. Trigonometry is also used to determine a position when shooting a star for instance with a sextant. Our modern Global Positioning Systems (GPS) also use trigonometry to calculate a position. Your smartphone therefore uses trigonometric ratios to decide where you are. A pilot and a ship's navigator use bearings to express the direction they want to travel. Trigonometry will then inform them of the distance which they need to travel. As you can read trigonometry plays an important role in our every day lives. It therefore also plays an important role on your maths exam! If you want to pass your IGCSE GCSE Maths exam then you will need to understand trigonometry and how the various ratios can be use to calculate lengths and angles. Study therefore during your maths revision the following sections in which I explain to you in detail what trigonometry is and how you can use it.