Topic 10 Year 8 Mathematics
Mathematics | |||
Topic | Angles in polygons | ||
No of lessons | 12 | ||
When is it happening | Term 3 Year 8 | ||
What will students learn |
Students use their understanding of angles in triangles from year 7 to build up to a proof for the sum of the interior angles in polygons with 4 or more sides by dividing into triangles. The perspective is then shifted to investigate the sum of the exterior angles of a polygon and students develop an understanding of the relationship with between the exterior and interior angles. Students solve a variety of problems using the angle relationships built up in this unit and in previous units. |
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Key Knowledge that students should know at the end of 'Topic' | This is the knowledge that students will meet for the first time in this topic | Know the sum of interior angles of a triangle and use to solve angle problems (revise from Year 7) • Explore different methods for finding the sum of the interior angles of polygons by splitting the shape into triangles • Generalise different methods for finding the sum of interior and define the sum of the exterior angles of a polygon • Use the sum of the interior and exterior | |
This is knowledge that students may have met before but will need to deepen their understanding |
Review angles including angles in parallel and perpendicular lines. |
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Key Skills that students should be able to demonstrate at the end of 'Topic' | This is the skills that students will meet for the first time in this topic | using a protractor | |
This is skills that students may have met before but will need to develop | Drawing different types of angles | ||
Key vocabulary that students should know and understand | Adjacent, vertically opposite, exterior, interior, polygon, | ||
The Big Question | What do the interior angles in a polygon sum to? | ||
Key questions that students should be able to answer at the end of the 'Topic' |
What is a regular polygon? | ||
Can I find missing angles in isosceles triangles? | |||
What are the angle rules? | |||
What do angles in a pentagon sum to? | |||
What is an icosagon? | |||
Can I find missing angles in a pentagon? | |||
How do I find exterior angles of polygons? | |||
Can I use the sum of the exterior angles to find individual angles? | |||
Are exterior angles in triangles always the same? | |||
Can I find missing angles in triangles? |