Steps of construction:
I. Draw a line segments ER = 4.5 cm.
II. With centre at E and radius = 7.5 cm, draw an arc.
III. With centre at R and radius = 6 cm, draw another arc to intersect the previous are at O.
IV. With centre at R and radius = 6 cm. draw an are on the side opposite to R.
V. With centre at O and radius = 4.5 cm, draw another arc to intersect the previous arc at M.
VI. Join RO, EM, EO and MO.
Thus, EROM or MORE is the required parallelogram.