We use this theorem:
If the diagonals of a quadrilateral bisect each other, the
quadrilateral is a parallelogram.
1. Draw a line 5.2 cm long.
2. Open the compass to 1/2 the length
of the shorter diagonal (1/2 of 6cm is 3cm)
3. Placing the sharp point of the compass on the right end of the
line, and swing an arc (the one I have in green).
4. Open the compass to 1/2 the length
of the longer diagonal (1/2 of 6.4cm is 3.2cm)
5. Placing the sharp point of the compass on the left end of the
line, and swing an arc (the one I have in red).
6. Draw a line 6cm long from the right end of the line through
the point where the arcs cross.
6. Draw a line 6.4cm long from the left end of the line through
the point where the arcs cross.
7. Draw in the other three sides of the parallelogram.
Edwin
