It will be 3 hours until they are the same hight
ANSWER

EXPLANATION
We use the sine rule for solving triangles.
This is given by the formula,

From the triangle,

We multiply both sides of the equation by 60 to get,


We solve for x to obtain,


To the nearest tenth, we round to one decimal place to get,
4 1/7 = (4*100) +(1/7 of 100)= (400+ 14.28)= 414.28
The answer is 414.28