There are 20 miles is Sheng from his home.
Most of the time it will be Length x Width x Height.
If you can't read it, I'll do my best to translate:
Z) 10^2 + 5^2 = 125
√125 = 11.18 = Z
Y) tan-1(5/10) = 26.57°
90 + 26.57 = 116.57
180 - 116.57 = 63.43°
5 ÷ sin(63.43) = 8.88 = Y
X) 11.18^2 + 8.88^2 = 203.8468
√203.8468 = 14.28
14.28 - 10 = 4.28 = x
All numbers are rounded to 2 decimal places, if you need any explanations for why I did something then just let me know :)
I hope this helps!