calculateAreaTrapezoid()

Step 1: Define the Function

To begin with, we need to define our function. In JavaScript, a function is defined by using the function keyword, followed by the name of the function, and parentheses (). The curly braces {} enclose the code inside the function. Inside the parentheses, we add parameters. Parameters are variables that the function uses to perform actions. For our trapezoid area calculation function, we will define it with two parameters: base1 and base2 which represent the lengths of the two bases of the trapezoid, as well as height which signifies the height of the trapezoid.

function calculateAreaTrapezoid(base1, base2, height) {
}

Step 2: Write the Formula inside the Function

The next step is to write down the formula to calculate the area of a trapezoid inside our function. The formula for the area of a trapezoid is ((base1 + base2) / 2) * height. Simply put, you add the length of the two bases, divide it by two, and then multiply the result by the height of the trapezoid.

function calculateAreaTrapezoid(base1, base2, height) {
  var area = ((base1 + base2) / 2) * height;
}

Step 3: Return the Result

Now, we want the function to give us the calculated area when we call it. We do this by using the return statement. The return statement stops the execution of the function and returns a value from that function.

function calculateAreaTrapezoid(base1, base2, height) {
  var area = ((base1 + base2) / 2) * height;
  return area;
}

Step 4: Call the Function

Finally, to use our function, we need to call it. In JavaScript, a function is called using the function name followed by parentheses (). Inside the parentheses, we put the arguments, which are the values passed into the function's parameters. Let's say the lengths of the bases are 5 and 6 units, and the height is 4 units.

calculateAreaTrapezoid(5, 6, 4);

Conclusion

And there you have it! We have successfully created a function in JavaScript that calculates the area of a trapezoid. The complete code is:

function calculateAreaTrapezoid(base1, base2, height) {
  var area = ((base1 + base2) / 2) * height;
  return area;
}

calculateAreaTrapezoid(5, 6, 4);