Best Math Lesson EVER!By: Angela Yedersberger

Paper folding…

Story of Sadako

Geometry definitionsLine of symmetry – a line that divides a

shape into 2 congruent parts that can be matched by folding the shape in half

Fold…

Geometry definitionsCongruent polygons – Two polygons

are congruent if their corresponding sides and angles are congruent

Similar polygons - Two polygons are similar if and only if the corresponding angles are congruent and the corresponding sides are proportional.

Geometry definitionsParallel lines - Two lines in the same plane

that, no matter how far they extend, do not intersect with each other. Parallel lines are the same distance apart at any given point.

Perpendicular lines - Two lines that intersect to form a 90° angle.

Open up: Where are the lines of symmetry? Which triangles are congruent and which are similar? Find 3 things (side, angle) from each triangle compared to predict.Which lines are parallel and which are perpendicular?

Fold Sides over :

Open up on both sides:

Fold on both sides:

Fold up:

Crane:When unfold ask the question:Is the square (diamond) in the center similar to the square of origami? Prove it using the theorems created earlier.

Questions?Did you see any other mathematical

lessons in making a crane exercise?