Nichito is right about lines 57 & 58 - they have no place in this program, they do nothing useful other than cause it to end before displaying your results. His revision to the calc function body does not change anything, just compresses three lines into one. Saves a couple assignment operations, that's all.

As to the erroneous area calculations, step through the function using the problem values (9,7,3). You should always solve by hand using the algorithm you implement to verify it. In this case, you'll find that your 's' value is 9. What's the value, then, of s-a? What happens when you use that result in the multiplications?

Your code is not giving the correct perimeter. It's giving 1/2 of the perimeter. You need to store the perimeter separately from the 's' value you use in calculations.

And lastly, the value you calculate for 's' is not correct, in most cases. Remember that dividing integers gives only an integer result, so 9/2 is the same as 8/2. You're storing to a double, so do the arithmetic as a double, divide by 2.0.