If statements are ignored

I have a simple calculator for finding the dimensions of a couple shapes. It's supposed to be set up so the first function has a set of if statements that trigger one and only one of the other functions based on user input. But instead it's triggering all of them no matter what my answer is. It skips the prompt for the circle one and goes through the prompts for the other two. It does give me a result for all three in the console and the console keeps telling me, no matter what input I put in, the answers to my shape functions is NaN. There's definitely a variable problem there but I can't figure it out. The console isn't bringing up any errors to me right now. Sorry there isn't a comment for everything yet.

//Lee_Matthew_Functions_Assignment_5/26/2015

        //Main Function

        function theConjurer() {
            firstQuestion = prompt("Hi! This is my shape dimension calculator! I have three different shapes in this version but I can always add more! For now I have these three:\nCircle Area\nSphere Volume\nRectangular Prism Volume\n\nEnjoy!!!"); //The answer to this prompt is supposed to spring one of the functions below.

            if(firstQuestion === "Circle" || "Circle Area") { //If the answer is one of these strings, then it triggers the circle area function.
                calcCircleArea();
            }

            if(firstQuestion === "Sphere" || "Sphere Volume") { //This one triggers the sphere volume function.
                calcSphereVolume();
            }

            if(firstQuestion === "Prism" || "Rectangular Prism" || "Prism Volume" || "Rectangular Prism Volume") { //This one is for volume of a rectangular prism.
                calcPrismVolume();
            }

            else {  //Anything else just brings up another prompt for the same answers.
                firstQuestion = prompt("Sorry, that's not one of the options I have right now. Try again!");
            }
        }

        theConjurer(); //To automatically bring up the starting function.


        //Function for Dimensions of a Circle

        var pi = 3.14; //pi rounded down to the hudredths place.

        calcCircleArea(pi, radius); //Variable declarations.

        function calcCircleArea(p, r) { //
            var circleArea = p * Math.pow(r, 2);
            console.log("The circle you've entered is " + circleArea + " square units!");
        }


        //Function for Volume of a Sphere

        calcSphereVolume(fourThirds, pi, radius);

            var fourThirds = (4/3);
            var radius = prompt("Do you know the diameter of your sphere? Just half that is your radius! What's the radius?"); //User input for the shape's radius.

        function calcSphereVolume(f, p, r) {
            var sphereVolume = f * p * Math.pow(r, 3);
            console.log("Your sphere is " + sphereVolume + " cubed units! Congradulations!");
        }

        //Function for Dimensions of a Rectangular Prism

        var length = prompt("What's the length of this prism?"); //User input for the shape's length.
        var width = prompt("What's the width?"); //User input for the shape's width.
        var height = prompt("What is the height?"); //User input for the shape's height.

        calcPrismVolume(length, width, height); //Storage for the above three variables.

        function calcPrismVolume(l, w, h) { //Function and its parameters.
            var prismVolume = l * w * h; //New variable made from multiplying those parameters.
            console.log("Your prism is " + prismVolume + " cubed units!"); //Output of shape's area.
        }