No, yes, no, yes
What part of comparing number values do you not understand? Most folks figure out enough about place value to be able to answer this by 3rd grade. If there's something about this question that really stumps you, please advise in the comments.
The solution is false!
3.1 would become a fraction that will be calculated back into a decimal by the 4th power making it 92.3521=3,600.. so the equality is false because the left hand and the right hand side are different.
A = (pi) * r^2
A = 3.14 * 11^2
A = 3.14 * 121
A = 379.94 miles
the given figure is a rhombus, so it's area =

where, d1 and d2 are diagonals of the rhombus,
and since, the diagnonals of rhombus bisects each other, the values of their diagonals are
(2 × x) and (2 × 15) =》2x and 30 respectively,
so, by finding the area using the given diagonals and equating it with the real area, we get :
=》

=》

=》

=》

so,
value of x = 10 units