Properties of Parallelograms
- Author:
- Irina Boyadzhiev
- Topic:
- Symmetry
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.
- 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.
- 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.