C++ statements question

Question

Given a double variable named areaOfSquare write the necessary code to read in a value into areaOfSquare and print out the length of the side of that square.

If any value read in is not valid input, print "INVALID"

Answer 1

As a partial answer addressing what might be the harder part of the question, you can call the method good() on the cin object after attempting to read in a double, which returns true if reading the double was successful and false if it was not successful, e.g.

cin >> areaOfSquare;

if (cin.good())

...

For the calculation part of the answer, you can use the fact that the input is the area of the square and the formula for area of a square is side * side or side². Look at the math library for the square root function.