Making Kites Mathematics
Sep/100
Mathematics! Yayyyy!?
Hi, just need a wee bit of help with my trig h/w:
A boy who id 1.2 metres tall flies a kite on a string of length 36 metres. The string of the kite makes an angle of 62 degrees with the horizontal. What is the HEIGHT of the kite above the ground?
Btw, the ‘HEIGHT’ is just to emphasise it… its in bold in the book. lol Thanks! x
Draw a diagram. Ignore the boy’s height for now.
From the kite, draw a line straight down. Draw another line horizontally from the boy’s hand. Now you should have a triangle, made of these 2 lines and the string of the kite. The angle at the boy’s hand is 62 degrees, and the length of the string is 36m, so draw those in.
Now you need to use trigonometry. You know the length of the hypotenuse, and you want the length of the opposite side. So you are using Opposite and Hypotenuse. The trig function you need is sine (cos it works with Opposite and Hypotenuse).
So, sine 62 = Opp / Hyp
and we know hyp = 36m.
So the ‘opposite’ side, the one we want, is 36 x sin62.
Work that out on your calculator.
Then, add on the boy’s height to find how high the kite is above the ground.
Kites – Making Math Fly