The angles of the sun.

Simple version.

To read a more complicated version continue... 

There is a relationship between the angle of the sun in the sky and latitude.

• You will need a protractor.
• A sheet of paper because it will show the shadow length easily.
• A straight stick.
• This is not an accurate method, but it is a good way to begin to understand how latitude and declination affect shadows.
• This method can only be used when the shadow is at its shortest.

At midday.

Lay the paper on the ground, get the paper as flat as possible and then push the stick as straight as possible into the ground.

Draw a line from the bottom of the stick, along to the top of the shadow on the paper.

Next lay the stick down and draw along its length on the paper so you have two lines, at 90 degrees to each other.

Use a protractor to find the angle of solar elevation.

Call it ASE.

As long as you know the latitude, and  drew the shadow when it was shortest (midday), you can find the angle of solar declination.

Here's how:

• Solar declination = ASE + latitude - 90 (degrees).

• ASE = 90 - latitude + solar declination.

• Latitude = 90 - ASE + solar declination.

If you want to experiment with figures.

• This site gives the angle of solar elevation [LINK]
• Find your latitude [LINK]
• Solar declination at the equinox (22nd March/ 22nd September) is 0

Notes:
"Local Noon" is the exact time when the Sun reaches its highest point in the sky. This is also the time that it crosses the meridian. 

The Meridian is an imaginary line that stretches from North to South.

The position of the Sun, as compared to the celestial equator is called Solar Declination. 

The Celestial Equator is an imaginary line in the sky stretching East to West.