Construct a rectangle ABCD whose adjacent sides are 11 cm and 8.5 cm.

Steps of construction:

Step 1: Draw $A B=11 \mathrm{~cm}$

Step 2: Make $\angle A=90^{\circ}$

$\angle B=90^{\circ}$

Step 3: Draw an arc of 8.5 cm from point A and name that point as D.
Step 4: Draw an arc of 8.5 cm from point B and name that point as C.
Step 5: Join C and D.
Thus, ABCD is the required rectangle.