This activity sheet guides students through an investigation with parallelograms. Students first are asked to remember the definition of a parallelogram. Students make one parallelogram from a set of parallel lines and a ruler and use two other given parallelograms to compare angles, sides, and diagonals of the three parallelograms. Patty paper, rules, and protractors can be used to compare the various parts of the parallelogram. Students make observations about the angles, sides, diagonals, and parts of the diagonals from the three parallelograms to discover the properties of a parallelogram.