1. The four straight lines make a square (shaded grey).
GM4.1 Support Starter
The four straight lines make a square (shaded grey).
One of the straight lines has the equation y = 10.
What might the equations of the three other straight lines be?
Preamble
This open-ended investigation is probably most efficiently done in pairs, with a drawing together of ideas from the whole class at the end. It revises previous work on straight lines parallel to the axes. For some groups it may be necessary to indicate which line y = 10 might be. A supplementary question could be ‘How can you tell the length of the sides of the square from the equations of the four lines?’
Pupils could also be encouraged to venture into negative coordinates.
Possible content
Equations of vertical and horizontal lines.
Resources
Squared paper may be needed by some pupils, although most may be able to perform the task just by sketching a rough grid and straight lines.
Solution/Notes
Pupils’ own answers/suggestions.