• question_answer In the figure below PQRS is a parallelogram. Side $QR=10\,\,cm$ and a perpendicular $AB=10\,\,cm$ as shown above. Find area of parallelogram A)  100 sq. cm.   B)  50 sq. cm.     C)  75 sq. cm.                  D)  25 sq. cm.

If you look at the figure with QR as base and AB as height, (by mentally rotating the figure), Area = base $\times$ height $=10\times 10=100\,\,sq.cm.$ Mind of a mathematician: Students should not only multiply numbers but also see how the units are getting multiplied, for e.g. $acm\times cm=sq.\text{ }cm.$$cm\times cm\times cm=c{{m}^{3}}$. The idea will help you not only in maths but also in physics and chemistry where dimensional accuracy is very important.