Answer:
C - 9 cm
Step-by-step explanation:
We can use the Pythagorean theorem to figure out the missing side length, in this case, X.
The Pythagorean theorem states: a^2 + b^2 = c^2, with c being the hypotenuse. We have the side length of the hypotenuse which is 15, and we have another side length of 12. Let's put these back in our equation:
a^2 + 12^2 = 15^2;
If we simplify the squares by simply doing them: a^2 + 144 = 225;
Now let's subtract 144 from both sides to isolate the variable, a:
a^2 = 81;
Now we square both sides to find a:
a = 9
The missing side length is 9 cm.
