Friday, 8 June 2012

SOLVED: Challenge Question 2

If you are the first to solve this problem I will give you complete set of the Richard Feynman Lectures on Physics (read up upon the Feynman Lectures on Physics).


A man, who is 1.65m tall, wishes to find the height of a tree with a shadow 36.52m long. He walks 24.12m from the base of the tree along the shadow of the tree until his head is in a position where the tip of his shadow exactly overlaps the end of the tree top's shadow. How tall is the tree? Round to the nearest hundredth.

Leave answers either in the comments box or contact me with the answer through our contact page or email me at


  1. The tree is taller than the man.

  2. I got 4.86 meters. It seemed to easy for a challenge question, so let me know if I did something wrong.

    I set up a proportion based on the two similar triangles one can create with the given information.

    12.4 / 1.65 = 36.52 / X, solving for X (the tree's height) yields 4.86 meters.

    1. That is in fact correct! It is a pretty easy challenge question but demonstrates how real life problems can be easily modelled by simple maths.

      If you want your prizes either reply here with your email address or send it to me via the contact page:

    2. Alright, sent you an email via the 'contact page'. I'll be on the look out for future challenges haha. Nice blog - the post on religion / existence is interesting to say the least, and I share a similar view as you on both topics.