Consider triangle WBG, where points W, B and G represent Weather Station, Balloon and Ground, respectively. This triangle is right with right angle at vertex G. The legs of this triangle are GB and GW, the hypotenuse is BW.
From the question you know that GB=4 km and GW=1 km. By the Pythagorean theorem,

Answer: nearly 4.123 km
You can't
Unless you have a special type of key board, you can only represent fractions with /. This is for a reason however, / also means divided by and that's what you're doing when you write a fraction. You divide the numerator by the denominator.
Sorry I can't give the answer you're looking for
Answer:
The value of x will be 8
Step-by-step explanation:
We have given that 
We have to find the value of x
As 
For finding the value of x we have to square both side
On squaring both side
We done squaring both side for easy simplification

So x = 8
So the value of x will be 8
So answer will be 8