Is it not a simple question and simple procedure ?
Plot a point A in the middle of the paper. Draw AB horizontally with AB = 6.5cm with a scale. Then At A, draw a vertical line using the protractor or any other way, so that the angle at A is 90 deg. Mark A, B. Now on the perpendicular line mark D at 3.8 cm.
Now at B using the protractor draw a line inclined towards DA, with an acute angle of 70 deg. Now mark C on this line at 5.5 cm length. Join CD and CB.