measuring distance by triangulation and parallax

[jgwollmann]

How come my Trigonometry professor is incapable of teaching in this manner, which is both practical, and remarkably simple and proficient?

And educators in America wonder why our children cannot compete in math and science.. We don't know how to teach!

[hm20010]

There is a way simple to check distance by triangle. Only needs pencil, ruller, and paper. No need protractor nor compass. Only one distance must be known for scale, the rest can be calculated. Can be used to create scale map, and to calculate height of an object from a distance. Accurate enough to check landscape distance, landscape area, landscape planning, etc. Simple enough to play treasure hunt game.

maruzar.blogspot.com/2011/12/d­istance-measure-by-paper-ruler­-and.html

[ProtossGod100]

I finally can measure distance from a far away place. I am 12 by the way :).

[smellybridge]

Brilliant! On the top of a hill near me I'm sure I can see Wirral, some 50 miles away. Now I can find out and see just how far those distant hills are.

Many thanks!

[happyjihad]

"broad and raging torrent"

hahahah.  nice video

[robertlewisvazquez]

this is how math should be applied in classes so kids will have an idea where to use math. Great video!!!!!

[44eastman]

Sorry , Tried it & i`m not getting the same answer ?. 10 divided by 6.5 ? Thanks

[fizzicsorg]

It is not 10 divided by 6.5 degrees it is 10 divided by the tangent of 6.5 degrees. The tangent of 6.5 is 0.114 so the distance X is 10/0.114 which = 88m to the nearest whole number.

[baeronautics]

@fizzicsorg i know a simply amazing method to find the distance if three angles are given and we have to finnd the diatance! yay

[44eastman]

Where does the 0.114 Come from ?

[fizzicsorg]

).114 is the tangent of the angle 6.5 degrees

[WorkableWizard]

@fizzicsorg so sorry, but how do you find .114 to be the tangent of 6.5? i am trying to work the same problem but x = 10 over tan 25 degrees. how would i find the tangent of 25 degrees? thanks for the help

[fizzicsorg]

@WorkableWizard The tangent of an angle in a right angled triangle is the ratio of the two shorter sides. More exactly the tangent is the ratio of the length of the side opposite the angle to the length of the side next to (or adjacent) to the angle. Of course the other way is to look up the tangent of 6.5 degrees on a calculator and that is 0.11393 or 0.114 to three significant figures.

I'm not sure if that helps at all !

Roger at fizzicsorg

[baeronautics]

@fizzicsorg how long should be the base line can we put it as long as we want what or why not?

[masbhrl]

According to what i know this way is used for not far a way stars

But for more distances they use the red shift

[yourrealmother]

Have they used voyager 1 for parallax measurements of stars? It is now over 100 AU from earth, so measurements from very distant stars could be made or much more accurate measurements for closer stars.

[fizzicsorg]

So far as I know, the instruments for such measurements are not available on Voyager