Question

How do you find the diagonal of a rectangle whose length is 12 in. and whose width is 9 in?

Answer 1

`15` in. units

Explanation:

The length, width, and diagonal form a right angled triangle, with the diagonal as the hypotenuse.

Hence, Pythagoras Theorem is valid and may used to solve as follows :

`d^2=12^2+9^2`

`therefore d=sqrt(144+81)=15`

Note we only consider the positive square root since the diagonal is a distance and cannot be negative in this case.