See the figure.
becomes an equilateral triangle with edges of cm.
First draw rectangle with and cm.
Next you draw the center of and point in such a way that .
Now you can draw pentagon .
See the figure.
See figure at a. Just divide each edge into three by measurement. This is allowed because the figure is a parallel projection.
See figure at a.
No, the base is not an octagon with equal edges. There are edges of cm and edges of cm.
See the figure.
They are equilateral triangles with edges of approximately cm.
A cube.
Let it be checked, when in doubt.
Both triangles have a base of cm and a height of approximately cm.
That height is the line segment from to the center of of the line segment from to the center of . When you draw full scale you can measure those heights.
The height of a trapezium is approximately cm.
You measure that height in a triangle through or and parallel to .
See the figure.
See the trapezium below.