So this is going to create a right triangle which you and his run will create the hypotenuse, so we will use
a^2+b^2= c^2
a and b are given... 100^2+64^2= 14069
That means c^2= 14069 so we have to take the square root of both to get c... which gives us 118.7265766373 which to the nearest meter is 119.