Mrs. Whalen’s Kindergarten Math Lesson #56: Review Geometry
All of these shapes are flat shapes. They can not stand up. If I cut them out they could not stand up because they are not solid shapes. rectangle square triangle hexagon circle
Let’s watch! https://www.youtube.com/watch?v=htcuPenTg38
I see a triangle in front of a hexagon. A hexagon has 5 sides and 5 corners. A triangle has 3 sides and 3 corners.
A square has 4 sides and 4 corners. side corner
These two triangles are the same. They have the same number of sides and same number of corners.
These two shapes are different. A circle has no corners and a rectangle has 4 corners. corner
Some shapes are solid. The shapes can stack on top of each other, slide around or roll. They are 3-dimensional shapes or 3-D shapes.
Let’s watch! https://www.youtube.com/watch?v=K9L9l86N-xM
Both of these shapes are closed figures. A closed figure is where all of the sides connect.
The triangle and square are closed. The sides that make up these shapes meet to form a corner. corner corner
This is a closed circle. This is an open circle.
Both the cube and the square are made up of straight lines and are closed figures.
Let’s move triangles over to see how many small triangles make a large triangle.
Let’s move triangles over to see how many small triangles make a large triangle. 1 2 3
Let’s move triangles over to see how many small triangles make a large triangle. 1 4 5 2 6 3
For the last 3 spaces we have to turn the triangles upside down. 1 4 5 2 6 3
For the last 3 spaces we have to turn the triangles upside down. 1 • 7 4 5 7 2 8 6 9 3
It took 9 small triangles to fill up the large triangle. 1 • 7 4 5 7 2 8 6 9 3
Let’s make a house together. You help me. You draw a house using shapes on your paper with me. First let’s start with a square.
Next draw a rectangle in the middle of the bottom of the square. This will be the door.
Goodbye! See you next time!