This is the first section of Chapter 11, "Geometry and Measurement Relationships". The learning goal for this section is to "Explore the relationships between the dimensions of a cylinder and the dimensions of its net". We start this section with an introductory example, where students must find the circumference of a lid and compare it with the dimensions of different labels, to see what matches. Since this is the beginning of the chapter, we define the concept of area, namely "The number of square units needed to cover a region". We then look at a couple of formulas for calculating area, with the understanding that we will soon be calculating the surface area of 3D objects.
Finally, we look at nine 2D figures for which we can calculate the area. In the notes, I didn't add the formulas for circumference or area of circles. If you want to learn more about that, Khan Academy has a fantastic explanation.
- Circumference and Area of Circles. This explains how to calculate, well, the circumference and area of circles.
- Circles: Radius, Diameter, Circumference and Pi. This 10-minute video gives a full introduction to the parts of a circle and their basic mathematical properties.
- Labelling Parts of a Circle: Goes over the concepts of radius, diameter, centre and circumference.
- Radius, Diameter and Circumference. A couple short word problems to help check your understanding.
- Area of a Circle Explanation. Explains how to calculate the area of a circle.
- Area of a Circle Word Problems. Check your understanding of how to calculate the area of a circle.