We are given that the area of a triangle is 600 square feet.
To find the altitude of the triangle, we need to determine the value of the corresponding base, which is $X$ feet.
The formula for the area of a triangle is:
Area = (base * altitude) / 2
Given that the area is 600 square feet, we can write:
600 = (X * altitude) / 2
To find the value of $X$, we can rearrange the equation:
(X * altitude) = 600 * 2
X * altitude = 1200
Now, we are given that the altitude is 40 feet, so we can substitute this value into the equation:
X * 40 = 1200
Dividing both sides of the equation by 40, we find:
X = 30
The value of X is 30.
The answer is: 30
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
The area of a triangle is 600 square feet. Find the altitude, in feet, of the triangle if the length of the corresponding base is X feet.
If we know the answer to the above question is 40, what is the value of unknown variable X?

### Answer:
