# How do you find the area of a rectangle if the length of one of it's sides is 3m and diagonal is 9m?

Oct 15, 2015

$25 , 456 {m}^{2}$

#### Explanation:

Form Pythagoras Theorem, we may find the length of the other side (x) since the two sides (x and y) and the diagonal (d) make a right angled triangle with the diagonal as the hypotenuse.

$\therefore {d}^{2} = {x}^{2} + {y}^{2}$

$\therefore x = \sqrt{{9}^{2} - {3}^{2}} = \sqrt{72}$ m

Hence the area may be given by length x breadth as follows :

$A = x y = 3 \sqrt{72} = 25 , 456 {m}^{2}$