Answer: The height of the monitor is 12 inches.
Explanation:
First, you need to acknowledge the Pythagorean Theorum,
+
=

You already have the c and the b , so you just have to plug them in to find a!
This is what it looks like when you substitute:
a² + 16² = 20²
Then, simplify.
a² + 256 = 400
Now, to isolate the variable, you have to move 256 to the other side. This, of course, means it changes from a positive to a negative number.
a² = 400 - 256
a² = 144
Now, you have to remove the square root from a. But, don’t forget, what you do to one side, you have to do to the other side. So, your equation will now look like this:
√a² = √144
The square root of a squared is obviously just a! And the square root of 144 is 12. Therefore, we now know that:
a = 12
So, the height of the monitor was 12 inches.