Given that this is a right triangle, we can use the Pythagorean theorem. Our theorem can be described as a^2+b^2=c^2
Our a and b values will always be our legs, aka the lines that form the right angle. In this point, We have an a value but do not have a b value. We can assume that A=7 but B=X.
The C value will be represented by our hypotenuse, which forms opposite of the right angle. In this case, our c= 12. Lets plug in what we know.
a=7
b=x
c=12
7^2+x^2=12^2
Our first step is to square everything, except the unknown number.
49+x^2=144
Now that we have that, We can solve it like any other equation. Lets subtract our 49 first.
x^2=95
Now that we have this, we will have to do the opposite of squaring number. The opposite of squaring a number is a taking the square root of it.
This now makes it:
x= 9.74679434481
In this case, it can be rounded to 9.7 OR 9.8 (DEPENDING HOW YOU ROUND)
X= 9.7 OR 9.8 (DEPENDING ON HOW YOU ROUND)