Find the length of the longest side of a right angled triangle with the two smaller sides equal to 8 and 15.

As the triangle in the question is a right angled triangle we can use Pythagoras Theorem , a²+b²=c². c is the size of the longest size which is what we are looking for and a and b are lengths 8 and 15.Therefore c²=8²+15², c²=64+225, c²=289, c=sqrt(289), c=17. So the length of the longest side is 17