Download full OTA from Google and sideload it <| sep |> I knew he was having a 6 <| sep |> I have no idea what middle school corresponds too , so I might be way off . Anyway . Forget about the circles for now . They come later . Sine , tan and cosine are ratios of the sides of right angles triangles . Importantly it is independent of length . It ' s easiest to see by get a pencil and paper and working this out by hand . Draw a straight line 10 cm across the middle of a graph page and mark it at 5 and 7 cm . Get a protractor make the angle 20 degrees with the 10 cm line . Join them into a right angled triangle at all the markings so you have something like imgrefurldocidFB 2 UM 1 jdpoNcMtbnidwFymIBHfJ 5 MoM % 3 Avet 1 w 318 h 213 clientsafaribih 711 biw 1280 ved 0 ahUKEwiJ 9 cLdr 8 P Q A h X L G Z Q K H d p E BIsQMwgaKAAwAAiactmrcuact 8 . Now we ' re going to make a table with 6 columns and three rows . Measure the length from the end to each of the markings . Using the picture as a guide that ' s AE , AD , AB . Put these results in a column called Adjacent . Measure the hypotenuse as well so you have AF , AG , AC and put these in a new ' Hypotenuse ' column next to the Adjacent column . Then make a third column called Opposite and measure EF , DG , BC . The last three columns we ' re going to use our calculator . We want a column that is OppositeHypotenuse . A column that is AdjacentHypotenuse and the last column to be OppositeAdjacent . When you put all of those in the calculator you should notice a pattern emerge . Now go to the calculator and type in sin 20 , cos 2 and tan 20 . What do you notice ? Now to circles . What is the relationship to triangles and circles ? It ' s because you can make a right angled triangle in any circle . For example this 620 or tbn 1 . gstatic . comimages ? qtbnANd 9 GcRrtzNFMAsqsTCK 36 LnWMWfs 87 RVgLxBT 2 pcMfp 1 LuZH 0 bakmkA . Trig was ' made ' by noticing the pattern of ratios being the same for any angle . Basically it gives this somefunction angle number . In this somefunction can be sin , cos or tan . This gives the same output every single time . Just like 6 x 318 every single time . If we know 2 of those things we can find out the 3 rd .