Q&A for How to Draw a Parallelogram

The lines you're suggesting are already part of the perimeter of the parallelogram. If you're asking about diagonals, you would use a straightedge to connect the upper left to the lower right, and the upper right to the lower left corners.

Draw a straight line. Choose two points on it at a convenient distance from each other. Using those points as centers, inscribe two arcs of the same radius. Draw a straight line on one side of the first line and tangent to both arcs. You now have two parallel lines which will form two sides of the parallelogram. Draw another straight line through both parallel lines. This will be the third side of the parallelogram. Use the compass to mark a point on each of the original lines equidistant from their intersections with the third line. Draw a fourth line through the latter two points. That line will be parallel to the third line you drew. You now have a parallelogram.

You're drawing 90-degree angles with your protractor. Choose a different angle.

Draw a line segment 6 cm long. Label it PQ. At P use a protractor to draw an 80° angle from PQ. Extend the new line 5 cm from P to S. At Q use the protractor to draw a 100° angle from PQ. Extend that line 5 cm from Q to R. Connect R to S. RS will be 6 cm. You're done.

Typically you would place the B at the upper-left vertex and apply the other three letters in clockwise fashion. This is not an inflexible rule; you can really do it any way you'd like.

Any number of parallelograms could be drawn with a given base and height, but not knowing its interior angles prevents you from drawing a specific parallelogram. With that in mind, you can draw the base on a grid line (say, a horizontal line), then measure up (or down) the length of the height, mark that point, and draw another horizontal line through that point. Then draw two parallel lines, each intersecting both of the horizontal lines (at any angle), and you have a parallelogram.

Use the method(s) above, but make all four sides identical in length.