Regular polygons are 2d shapes. Each regular polygon has all sides the same length - equilateral, and all its interior angles are the same - equiangular.
This printable polygon sheet includes the ten 2d shapes starting at the 3 sided triangle, increasing in side number by one through to the 12 sided dodecagon.
Click on the image for a PDF version which is easy to print. Or click here for a larger jpg if you prefer