Ask "What is a triangle?". 2. Using Sketchpad, create a variety of shapes (examples and non-examples of triangles). Begin with open and closed shapes, and shapes with or without straight sides.

For example, a triangle made of paper would collapse much sooner than an arch made of steel -- an effect that was not demonstrated in this lab. The shape comparisons in this lab depend upon the ...

These reflected rectangles are example of congruent shapes ... makes it easier to visualise which two shapes are similar. Triangles ABC and DEF are similar. Triangle DEF is an enlargement scale ...