What is the value of x?
enter your answer in the box
13 is top 12 is bottem and the left is x

x = 5




Explanation:

We have a right triangle as indicated by the square angle marker. Two of the sides are known: specifically the hypotenuse (13) and one of the legs (12). The other leg (x) is unknown.

We can use the Pythagorean Theorem to find x

a = 12 is one of the known legs
b = x is the unknown leg
c = 13 is the hypotenuse

Pythagorean Theorem:
a^2 + b^2 = c^2
12^2 + x^2 = 13^2
144 + x^2 = 169
144 + x^2-144 = 169-144 ... subtract 144 from both sides
x^2 = 25
sqrt(x^2) = sqrt(25)  ... apply square root to both sides
x = 5 

Side Note: Keep in mind that x can't be negative so it doesn't make sense to use the plus/minus here. We'll only stick with the positive version.