Question

The length and width of a rectangle are 15 cm and 8 cm respectively. How do you find the length of a diagonal?

Answer 1

`17cm`

Explanation:

The length, width and diagonal of the rectangle form a right-angled triangle, with the diagonal as the hypotenuse, so Pythagoras Theorem is valid to compute the length of the diagonal.

`d^2=15^2+8^2`

`therefore d = sqrt(225+64)=17`

Note we do not consider the negative square root value since the diagonal is a length so cannot be negative.