Posted tagged ‘congruence’

Troublesome, tricky triangles of terror!

August 8, 2010

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.)