Coming up with the definition of a circle.

What is length of the radius? The distance between the center and a point on the circle. The distance stays the same. Try for a few circles by moving the slider. For each circle, try a few points on the circle (move X).

Three Reflection Lemma for Transformations

Find the three reflections that takes the first triangle to the second triangle.[br]Make sure that your construction is not distructable easily. (If I move the triangles, the construction should still work.)[br]Write out the proof of lemma. (You will need the three points transformation lemma.)

Tiling

Smiley, Move the slider back and forth.

Move the slider to see the animation.

Estimating the area of a circle using Hexagons

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