 All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars  perplexus dot info  Tackling a Tall Problem (Posted on 2005-03-11) I wanted to find out how tall the rugby posts at my local stadium were. Taking a handy rod as my standard unit of length, I went out to the field with the rod and a gadget for measuring angles from ground level.

I walked out 10 rods from one of the goal posts and measured the angle from the ground to the top of the post. Then, just to be certain my calculations would be as accurate as possible, I walked another 10 rods in the same direction, and measured the angle again. To be absolutely precise (as I'm a bit of a perfectionist), I walked a final 10 rods in the same direction and measured the angle a third time.

When I went home to calculate the height of the goal post, I was surprised to discover that the sum of my three angles was precisely a right angle.

How tall were the goal posts in rods?

 No Solution Yet Submitted by Sam Rating: 3.6000 (5 votes) Comments: ( Back to comment list | You must be logged in to post comments.) Solution, different method. | Comment 2 of 10 | arctan(h/10)+arctan(h/20)+arctan(h/30)-90=0

A little help from my graphing calculator gives me h=10, so ten rods.

Double-checking...
arctan(10/10)=45
arctan(10/20)=26.6
arctan(10/30)=18.4
45+26.6+18.4=90

 Posted by Caz on 2005-03-11 13:31:56 Please log in:

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