Calculating perimeter with missing lengths

Perimeter lesson looking at:
- finding one missing length when given the perimeter
- finding one side length of a regular polygon when given perimeter
- finding the missing lengths, then perimeter, on compound shapes when given the opposite sides

Lesson includes lots of examples, 3 quick questions as a mini plenary, a self check to direct students to appropriate starting points and a differentiated worksheet.

Thanks to donsteward's blog for providing some of the questions and activities.