# How Tall is It? Measure Something Tall Without Climbing It

The most accurate way to measure something is using a tape measure, but some things are too tall (or too scary) to climb with a ruler. Try the different methods for the same tree and see how similar (or different) the results are. These examples are all about trees, but would work for buildings, telegraph poles and any other tall structures.

#### Bending Over

Get an adult to walk away from a tree until they are just about able to see the top of the tree when they bend over and look through their legs. The distance they are from the tree is roughly the same as the height of the tree.This works because an adult bending over and looking up at the top of the tree creates about a 45 degree angle. This creates a triangle where the base and the height are about equal – so the distance from the tree is about the same as the height of the tree.

#### Using Shadows

On a sunny day, measure the length of a tree's shadow. Measure the length of the shadow of something of a known height (for example a person, a measuring stick or a pole). Divide the length of the tree's shadow by the length of the person, measuring stick or pole's shadow and then multiply it by the height of the person, measuring stick or pole – the answer is the height of the tree.#### Using Shadows #2

Stick a long stick in the ground (one or two metres tall if possible), and draw a circle around the base of it, so that the distance from the centre to the circle is exactly the same as the distance from the ground to the tip of the stick. When the tip of the shadow touches the edge of the circle, the length of the shadow is exactly the same as the height of the stick. Run to the tree and measure the length of the shadow – this will be the height of the tree.#### Using a Camera

Set up a digital camera on a tripod and get someone to stand next to a tree holding a measuring stick or a stiff tape measure, extended as far as possible (one to two metres long if available). Take a picture of the person and tree, with the tree taking up about half the height of the picture.On a computer, use the manipulation tool to copy a rectangle exactly the same height as the measuring tape or stick and paste it a number of times up the side of the tree and see how many times the measuring stick or tape needs to be pasted to measure the height of the tree. Multiply this number by the height of the measuring stick or tape measure to get the height of the tree.

#### Using a Stick

Choose a stick that is exactly the same length as the distance from fingertips (arm fully stretched out) to eye. Hold the stick vertically (arm at full stretch) and walk away from the tree until the tree height is the same as the stick. Measure the distance to the tree – this is its height.#### Tracking Tree Growth

People working in forestry use clinometers or theodolites to measure slopes and angles, and use these to calculate the height of a tree.Keep a record of tree heights over a year – how quickly do they grow? Do different kinds of trees grow at different rates? Try measuring the girth (the distance around the trunk) as well – be careful not to damage the bark.

Re: Why Oil and Water Don't Mix

Subscribe to Pewdiepie also... bobs or vagana?

Re: Growing Plants in Different Soils

this has been very helpful for my science experiment thank you

Re: A Bending Bone

The bones soaked in water won't change - it's the acid that affects the bones. And eating acid foods doesn't change the pH of the body so won't…

Re: Melting Points for Different Solids

Could you please practically research whether candle wax can melt at room temperature under reduced pressure?

Re: A Bending Bone

vinegar has acid so if we eat something that contains acid which is bad for bones so what will happen if we eat something that contains Acid!?

Re: Keeping Warm or Cold: Insulation and Conduction

Subcribe to Pewdiepie

Re: Melting Points for Different Solids

Pls can you do more melting points!!!!!!!!!

Re: Growing Plants Without Soil

this helped me chet on a test lol

Re: Pulling and Pushing: Magnetic Attraction

I want buy REPULSIVE FORCE magnat oil. Pl rep me

Re: Keeping Warm or Cold: Insulation and Conduction

My son is doing a science project and he has to use a can good can, so he's using an empty can of corn…