Here is a list of four points: (1, 1), (4, 1), (4, 3), (1, 3).

If you plotted all four and joined them up, what shape do you think you would get?

Each shape is drawn by plotting every vertex first, then joining the points in the order listed, with the last point going back to the first so the shape closes. The same rule builds a rectangle, a triangle, a pentagon, a shape that uses negative co-ordinates, and one surprise at the end. That last one has the same points as a square, but a different result.

Now we plot this kite together, point by point: (3, 1), then (5, 4), then (3, 6), then (1, 4). Always go across first, then up. We plot all four first, then join them in that order and back to the start. Before you join the last line to close it, say what shape you think it will be.

Today we draw four shapes, each one harder than the last. Remember: on a four-quadrant grid, go across first (left for a negative), then up or down (down for a negative).

• Rectangle: (−3, −1), (2, −1), (2, 2), (−3, 2)
• Triangle: (−4, −3), (3, −3), (0, 3)
• An arrow from six points
• The trickiest: a square from (−2, −2), (2, −2), (2, 2), (−2, 2), joined in that order so the sides do not cross