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 ...

Have the students notice that the triangle always has three sides. Have the students draw triangles using pencil and paper. Ask for examples of triangles that are very different and very similar. Ask ...

Definitions, examples, counter examples of similar triangles. (Prove) If a line is drawn parallel to one side of a triangle to intersect the other two sides in distinct points, the other two sides ...