#1

I have a quadrilateral which closely resembles a rectangle, but all the sides are different lengths, and none of the angles are exactly 90 degress. I don't know any interior angles. Can anyone think of a good way to find the angles without assuming one of them to be 90 degrees? I also have readings from a GPS at each corner, but I have no idea how to use those.

Thanks for any help.

Thanks for any help.

#2

Can you form a rectangle around the shape, going through all of the corners? If so, maybe you could work off the sides as parts of a triangle ...

#3

please post the problem/picture. i'm finding it hard to understand :x

#4

Jim has 8 apples.

Cindy borrowed 2 apples from Jim.

Why doesnt Jim be a man and EAT THE APPLES!

Cindy borrowed 2 apples from Jim.

Why doesnt Jim be a man and EAT THE APPLES!

#5

Scan it and we'll help

#6

Pictures please it really helps

#7

42

#8

you have point (coordinates) as in on a grid? that would really help. upload the problem.

#9

I don't have a picture available. I don't have the capabilities of scanning. I'll try to find some way of posting a picture.

#10

Paint.

#11

I don't have any grid coordinates, I have latitude and longitude from a GPS. And there's no "problem" to upload. This is a real life issue.

#12

please post an image

#13

hmm . dude . thats hard xD

#14

Scale map. That will give you the distances between each point. Then get some of the old trig functions out to work out each angle.

#15

I have distances of each side. I either don't know the trig, or the trig doesnt exist to help find the angles. Here's a drawing in paint. This is NOT TO SCALE. I just threw down some times to demonstrate exactly what I'm working with.

#16

a protractor?

#17

^I don't have a drawing that is to scale. If I did, I wouldnt be needed for this work.

EDIT: I also have latitude and longitude readings if anyone can show me how to calculate distance with those.

EDIT: I also have latitude and longitude readings if anyone can show me how to calculate distance with those.

*Last edited by TNfootballfan62 at Jun 30, 2008,*

#18

What are you trying to do? Find the angles in the corners? They could be anything.

I assume you have the resources to measure distances, in the same way you got the lengths of the sides, right? Measure a diagonal. Then work with triangles. Simple.

Oh, and by the way, using the metric system should also make things a little easier.

I assume you have the resources to measure distances, in the same way you got the lengths of the sides, right? Measure a diagonal. Then work with triangles. Simple.

Oh, and by the way, using the metric system should also make things a little easier.

*Last edited by Malakian88 at Jun 30, 2008,*

#19

^I didn't do the measuring. I'm solving this for my boss who did the measuring himself. He simply provided me with the drawing i provided, and asked i translate it to AutoCAD. I can't go out and make more readings. If I had a diagonal, I would've been done with this a long time ago. I do have GPS readings at the corners, though. Can anyone converat latitude and longitude to distance?

#20

^I don't have a drawing that is to scale. If I did, I wouldnt be needed for this work.

EDIT: I also have latitude and longitude readings if anyone can show me how to calculate distance with those.

Make a scale drawing then?

#21

Se,, as far as i can see the system is fixed. That means, there it is certain tain the angles are fixed and not variable, so there exists a way to find them out.

Try assuming lower left point to be the origin, and the lower line to be anlong the x axis. assume coordinates. right bottom point becomes (x1,0) top right becomes (x2,y2) top left is (x3,y3). and bottom left, of course, is origin.

5 variables, so you need five equations. use the distance in a formula to find the coordinates of the four points.

once you have the co ordinatess then all you have to do is find the angles between the lines right? so for that you find the slope of each line. and then for the angle between two lines, the formula is angle= (m2-m1)/(1+m1.m2)..where m represent slope of each line.

Try assuming lower left point to be the origin, and the lower line to be anlong the x axis. assume coordinates. right bottom point becomes (x1,0) top right becomes (x2,y2) top left is (x3,y3). and bottom left, of course, is origin.

5 variables, so you need five equations. use the distance in a formula to find the coordinates of the four points.

once you have the co ordinatess then all you have to do is find the angles between the lines right? so for that you find the slope of each line. and then for the angle between two lines, the formula is angle= (m2-m1)/(1+m1.m2)..where m represent slope of each line.

#22

^^I will, as soon as i find some angles.

^Thanks for the response. I'll go over what you posted and try to put something together if i can't find any info on converting these GPS readings.

^Thanks for the response. I'll go over what you posted and try to put something together if i can't find any info on converting these GPS readings.

#23

^I didn't do the measuring. I'm solving this for my boss who did the measuring himself. He simply provided me with the drawing i provided, and asked i translate it to AutoCAD. I can't go out and make more readings. If I had a diagonal, I would've been done with this a long time ago. I do have GPS readings at the corners, though. Can anyone converat latitude and longitude to distance?

I see.

Is this some kind of special assignment your boss has set you to see how good you are at finding ways to solve near-impossible problems? From the distances alone there is no way to find any of the angles. Take four sticks of these lengths (scaled down unless you have really long arms) and join them into a quadrangle with hinged corners. You'll find you don't have a rigid shape and can bend it into any combination of angles adding up to 360º. Your only hope is the GPS co-ordinates.

One degree of longitude can correspond to a whole range of distances depending on your latitude. One degree of latitude, on the other hand is ... *gets calculator* ... 111.13 km. Making one minute equal to 1.85 km and one second equal to 31 m. This way you can get some y-co-ordinates for your points, and from there you can figure the whole thing out.

#24

sin cos tan

#25

^I'm not retarded.

But, using a distance calculator online, i'm figuring it out. Thanks.

But, using a distance calculator online, i'm figuring it out. Thanks.

#26

For anyone interested in the solution, when i started calculating angles with the distances obtained from the GPS readings, one of the angles turned out to be 90 degrees, by chance.