What you will need;

Clinometer

Tape measure

Paper

Pen or pencil

Assistant

In this Instructable, I'll show you how to use a clinometer to measure the height of a tall object (for help constructing your own clinometer from basic classroom materials, click here).

What you will need;

Clinometer

Tape measure

Paper

Pen or pencil

Assistant

What you will need;

Clinometer

Tape measure

Paper

Pen or pencil

Assistant

Pick a spot to measure your object (I measured a telephone pole). You should be far enough away from your object that you can see the top of it, and you need to be on level ground with the base of the object. I like to set something down by my feet once I've picked my spot, so that I can easily come back to it.

use pithogres thrim a2+b2

Fantastic! Thanks a lot!

I used this in class with my students it worked great!

People have been mentioning the BSA method, which is fine, but the accuracy compared to a protractor and tape measure will be much less. And if you don't need accuracy, why even use the stick, just eye-ball it. (My two cents)

Coincidentally, I measured a telephone pole too.

Rather than making eye-level measurements, I made ground-level measurements, and measured the angle of elevation at night (since I was using a laser pointer for aiming).

The attached photo shows a level with integrated laser pointer, and a 360-degree protractor.

1) Focus on a point on the object (let's call it point A) and walk back from the object until the inclinometer reads 45º. The horizontal distance from the point on the ground directly under Point A to where you are standing, PLUS the height of your eye-level (because that's where the inclinometer is measuring 45º from) is the height of the point you are measuring.

2) Do the same thing, but at 30º, multiply the ground distance by 2 and at 60º divide the ground distance by 2. (Add the "eye level height" BEFORE you multiply/divide)

On 45 degree triangle it works out at root 2 which is 1.414.

So, soon as you see a 45 triangle you know instantly that the hypotenuse is 1.414 (whatever units you are using) long

same with a 60 - 30 being 1.732 units long.

Ratio of sides....had it drilled into us in technical college, can't seem to forget it now.

http://mathworld.wolfram.com/30-60-90Triangle.html

http://en.wikipedia.org/wiki/Special_right_triangles

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Using a twelve inch ruler held at arm's length, align the 12 inch mark with the top of the object and zero inches with the ground level at the foot of the object (adjust distance as required). Now get your assistant to mark the object with chalk or similar, or hold their finger at height of the one inch mark (commands such as up a bit, down a bit may help). Measure the height of the chalk mark or finger in inches, this is the height of the object in feet. Clearly only works to heights that one's assistant can reach, so around 80 feet or so. For taller trees, use the half inch point, this gives half the height in feet. For users of the metric system, a 30 cm rule and 3 cm would give one tenth the height at the mark.

my good compass has cotangent tables on the back for navigation purposes, same thing but on the horizonatl plane

Also note that fzumrk and hlanelee are elegant solutions.

Would the three of you be kind enough to post more for those of us who lost all those school applied maths somewhere in adulthood ??

It is so much fun to feel one can be (somewhat) clever again …

Thank you again !!!…

In your pictured example, you would measure the length of the pole's shadow. Then you need the height and shadow length for another object for comparison. You could use one of the nearby pipe bollards. Once you have the height and shadow length for the pipe bollard, the pole's height = (bollard height / bollard shadow length) * pole shadow length.