# Montessori geometry; angles.

I’m working through Cultivating Dharma’s geometry album with Heleyna. I haven’t used THESE freebies yet.

I am using the construction triangles and rods as well as one or two other bits from JMJ Publishing.

We started with the triangles some time ago and Heleyna can now name the three basic types of triangle; equilateral, isosceles and scalene with acute, obtuse and right angles.

Using the construction triangles from JMJ she has made various shapes.

Then I introduced her to the Montessori protractor.  It has little pegs all around the face of a full 360º protractor complete with fractions.

We started with a bent straw (not from the album) to make a right, acute and obtuse angle on the protractor face. Repeated this with acute being smaller than a right and obtuse being bigger.

We made more angles and triangles with rubber bands.

Then I introduced the insets for the protractor. For the first lesson she simple measured their angle on the protractor and then drew around them in her Geometry notebook.

As the insets are easy to use Heleyna can get on with measuring and drawing around them herself, with me simply there to add a bit of help if she asks.

The next lesson we used the paper rods to make triangles in her book and then to label the parts of an angle; vertex, side and amplitude.

We used the paper rods to make different angles.

I read her the story of Sir Cumference and the Great Knight of Angleland. This comes with a paper protractor. It’s a good, simple way of getting the facts across. We have a few Sir Cumference books now and I will probably buy more as we go along.

Having got the hang of measuring angles we started to use add angles. Heleyna would choose a piece for the Montessori protractor. A 90º or less piece. She would measure it and then draw round it and write the angle inside the shape. Then she would measure another shape (and acute piece). She would place that next to the first drawing and draw round it writing the angle inside.

Putting both pieces on the protractor she measures the new angle. We check it by adding the two angles together.

These lessons are done over  a few weeks and we repeat them through.

I think the tactile nature of the Montessori resources is a great help, and I can see how children aged 5 to 6 (Heleyna is 5) can get to grips with fairly complicated ideas if they can actually make it themselves.