15 Oct 2018 Uncategorized


Still on the outdoor theme today but this time with a fun Maths activity. And at the same time, children can appreciate the glorious Autumn colours at this time of year.


The aim is to measure a particularly tall tree, but a building will do if there aren’t any in the school grounds. You could pose  questions such as, “If this tree fell down in a strong wind, where do you think it would reach to in the playground? Would it fall on any buildings? How many metres high do we estimate it is?”.

So the question now is “How can we actually measure the tree without any climbing or broken bones?!” And the answer is – trigonometry.

Here’s how! Simply take a square piece of paper and fold it so that you have a right-angled triangle. Look along the longest side (the hypotenuse) of the triangle by holding a 45º angle in front of one eye with the triangle towards you. One of the short sides should be horizontal and the other vertical.


Now move back from the tree until you can see the top of the tree at the top tip of the triangle. Close one eye and use the other to look directly along the hypotenuse, until you see the top of the tree.


Mark this spot and measure the distance from it to the base of the tree. Add your own height to this, as you were looking at the tree from the height of your eyes off the ground. How close were you to your estimate? Do you have to keep your fingers crossed that the buildings are safe in a storm!

And if you fancy trying out some other methods, go to:



If you tried different ways, did you always get the same result?