How do you calculate the hypotenuse of a right angle triangle if the two shorter sides are 6 and 8?

As this is a right angle triangle, we need to use Pythagoras's Theorem. 

This says that the length of the longest side of a right angle triangle (the hypotenuse) is equal to the sqaure root of the sum of the squares of two other sides.

So in this case:

h = sqrt(6^2 + 8^2)

h= sqrt(36 + 64)

h = sqrt (100)

h = 10 :)

Fun fact - this is a special triangle known as a Pythagorean triple as all three sides are integers (whole numbers)