## Troublesome, tricky triangles of terror!

Triangles are the simplest of geometrical shapes – three connected straight lines form a triangle. Of course, we need ways to classify the different possible types of triangle (right-angled or not, equilateral, isoceles or scalene, etc.)

But that is old – you learned that information in primary school – early in secondary school you learned about the angles (summing to 180, acute, obtuse, complementary, etc). This year we want to be able to identify if two triangles are similar (same internal angles, different side lengths) or congruent (exactly the same – i.e. same sidelengths and same angles.)

Here are some videos – we may end up doing a similar project in class (you may want to look up what Aristarchus and Eratosthenes achieved with similar triangles).This is the first:

Here are the rest.

We are moving on to Trigonometry and Unit Circules as the next unit of study; this post may be updated with new information, so keep an eye on it.

See you in class.

**Explore posts in the same categories:**Mathematics

**Tags:** congruence, similarity, triangles

August 10, 2010 at 7:42 AM

Dear Mr G

I would like to apply an extension for the maths report due in today 4th period. You haven’t replied to my inquiry e-mails, so i’ll ask you for some help just to explain the things needed in discussion. Thank you!