I want some problems on trigonometry(mainly to find the length of a river)?

Answer 1

Surveying problems? At what level?

The classical plane trig type surveying problem hinges on angle-side-angle. For example:

You have a crew of 4 surveyors. There are 3 on one side of the river and one on the other.

Two of the surveyors have theodolites, and so can measure plane angles accurately. The set up on the same side of the river, a little way from it, along the river's general direction, a measured distance D apart.

The other two surveyor carry staffs and walk along the river. Periodically they stop and face each directly across the river.

At these times, the two surveyors with the theodolites take sightings and determine the angles from the line between them to the two staffs.

When they reach a point opposite the down-river theodolite, the up-river theodolite leap frogs to take the down-river position.

Given that:

- the two theodolites are 5 miles apart
- the angles to one staff position are 53 degrees and 37 degrees
- the angles to another staff position are 37 degrees and 53 degrees.

How far is each of the staff positions from the two theodolites and from the other staff position?

If problems such as this are too easy, then go to three dimensions: use mountain tops as your observation points, with observations including both elevation and bearing.

Then comes spherical trig - when the distances become great enough to take the Earth's curvature into account.

HTH.

Answer 2

that's person-friendly sufficient to take measurements from a map. First you would be able to desire to make certain the river's source. which will probable take merely somewhat discover ways to discover the interior of reach names of rivers. next you would be able to desire to make certain the place the river ends. If it joins a greater robust river, that's extremely person-friendly. besides the incontrovertible fact that, if it leads to a sea estuary, you would be able to desire to make certain the place the river ends and the sea starts off. that's in many circumstances performed with floats. they're going to cease moving downstream while they meet the severe tide. a sequence of readings would be taken to grant a advise place.