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. \[cm\times cm=sq.\text{ }cm.\]\[cm\times cm\times cm=c{{m}^{3}}\]. The idea will help you not only in maths but also in physics and chemistry where dimensional accuracy is very important.