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Then Listing 2 calls the toDegrees method, passing the value of angRad as a parameter and stores the returned value in a variable named angDeg .

Finally, Listing 2 calls the document.write method twice in success to display the angle values shown in Figure 5 .

Another exercise with a different viewpoint

Now let's approach things from a different viewpoint. Assume that

  • You know the value of the angle in degrees.
  • You know the length of the hypotenuse.
  • You need to find the length of the opposite side.

Assume also that for some reason you can't simply measure the length of the opposite side. Therefore, you must calculate it. This is a common situation inphysics, so let's see if we can write a script that will perform that calculation for us.

Please create an html file containing the code shown in Listing 3 and open the file in your browser.

Listing 3 . Finding length of the opposite side.
<!-- File JavaScript03.html --><html><body><script language="JavaScript1.3">function toRadians(degrees){ return degrees*Math.PI/180}//end function toRadians //============================================//function toDegrees(radians){ return radians*180/Math.PI}//end function toDegrees //============================================//var hyp = 5 var angDeg = 53.13var angRad = toRadians(angDeg) var sine = Math.sin(angRad)var opp = hyp * sine document.write("opposite = " + opp + "</br>") hyp = opp/sinedocument.write("hypotenuse = " + hyp + "</br>")</script></body></html>

The output for the opposite side

When you open your html file in your browser, the output shown in Figure 3 should appear in your browser window.

Figure 6 . Output for script in Listing 3.
opposite = 3.999994640742543 hypotenuse = 5

Computing length of opposite side with the Google calculator

We could also compute the length of the opposite side using the Google calculator.

The length of the opposite side -- sample computation

Enter the following into the Google search box:

5*sin(53.1301024 degrees)

The following will appear immediately below the search box:

5 * sin(53.1301024 degrees) = 4

This is the length of the opposite side for the given angle and the given length of the hypotenuse.

Interesting equations

We learned earlier that the sine of the angle is equal to the ratio of the opposite side and the hypotenuse. We also learned that the angle is thearcsine of that ratio.

If we know any two of those values ( angle , opp , hyp ), we can find the third (with a little algebraic manipulation) as shown in Figure 7 .

Figure 7 . Interesting sine equations.
sine(angle) = opp/hyp angle = arcsine(opp/hyp)opp = hyp * sine(angle) hyp = opp/sine(angle)

Getting back to Listing 3

After defining the radian/degree conversion functions, Listing 3 declares and initializes variables representing the length of the hypotenuse and theangle in degrees. (Note that the angle in degrees was truncated to four significant digits, which may introduce a slight inaccuracy into thecomputations.)

Get and use the sine of the angle

That angle is converted to radians and passed as a parameter to the Math.sin method, which returns the value of the sine of the angle.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Contemporary math applications. OpenStax CNX. Dec 15, 2014 Download for free at http://legacy.cnx.org/content/col11559/1.6
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