Here's a quick set of 25 flash cards to help with 2d geometry.
Each card has 6 answers on it, so it's really like having 150 cards.
Each card has a picture of a 2D shape, like a square. On the back, once assembled, you can quiz yourself on the name of the shape, the number of sides, the number of angles, the sum of interior angles, the right angles in the shape, and the pairs of parallel lines. The last page of 5 is blank so you can add your own.
Included in the set are:
acute, obtuse, right, scalene, isosceles, equilateral
dart, kite, rhombus, parallelogram, square, rectangle, isosceles trapezoid, right trapezoid
Regular Pentagon, Irregular Pentagon, Hexagon, Octagon