# Properties of Parallelograms

This applet can be used to see the properties of parallelograms.
• Drag any of the blue points to change the parallelogram.
• Click the "Duplicate" button to create a copy of the parallelogram. If necessary, adjust the position of the second parallelogram to match the colors of the angles of the original parallelogram.
• Drag the orange point to rotate the copy around the center of the parallelogram.
Use this symmetry to see the properties of the parallelograms.
1. Parallelograms
• Construct a general parallelogram.
• Click on the "Duplicate" button and if necessary, adjust the position of the second parallelogram to match the colors of the angles of the original parallelogram.
• Rotate the second parallelogram on 180 degrees around the intersection point of the diagonals. Use this symmetry to notice the three properties: the opposite sides are congruent, the opposite angles are congruent, and the diagonals bisect each other.
1. Rectangles
• Click on the "Hide Duplicate" button and drag the blue points to make a rectangle.
• Click the "Duplicate" button to show a copy of the rectangle and, if necessary, adjust the position of the second rectangle to match the colors of the angles of the original rectangle.
• Rotate the rectangle on 180 degrees around the intersection point of the diagonals. Use this symmetry to notice the three properties of the parallelograms.
• Notice the additional property of the diagonals of the rectangle - they are congruent.