Defining the length of sides in an irregular polygon

I think there are the only 2 ways:

1. Draw the 4 sides Polygon, and rotate to have the base side. Put an axis in the middle of base by guideline.
2. Transform the polygon in curves and remove middle side nods.
3. Draw 3 lines: 70, 100 and 220 mm in lower layer.
4. The base and the top sides lengths of Polygon apply by 70 and 100 mm lines.
5. Rotate 220 mm line in 90 degrees to be vertical, put the bottom nod on one to the end of 100 mm and rotate round the bottom nod to reach end nod of 70 mm. Then this side line: Object – Transform – Mirror, and finally, apply this gained shape on to the polygon.

The other way:
Start at point 3, and finally if you you have a gained shape: Object – Connect curves.