Mathematics
Base AB = 6.5 cm, BC = 4 cm and the altitude corresponding to AB = 3.1 cm.
Answer
Steps of construction :
Draw a line segment AB = 6.5 cm.
At B, draw BP ⊥ AB.
From BP, cut BE = 3.1 cm.
Through E draw a perpendicular to BP to get QR parallel to AB.
With B as center and radius = 4 cm, draw an arc that cuts QR at C.
With A as center and radius = AD = 4 cm, draw an arc that cuts QR at D.
Join AD, BC and CD.

Hence, ABCD is the required parallelogram.