Answer:
x = 5 in
Explanation:
In order to find the base of the triangle you have to use the formula
a² + b² = c²
In this formula, a and b represents the sides of the triangle, and c represents the hypotenuse, which is on the oposite side of the right angle. With this formula, any side of a right triangle can be found.
ps.: if the traingle is not a right triangle, meaning it does not have a 90° angle, this formula cannot be used
So, we are going to plug the known values in, 12 for a, x for b, and 13 for c, and solve for x.
a² + b² = c²
12² + x² = 13²
144 + x² = 169
x² = 169 - 144
x² = 25
√x² = √25
x = 5
Now, if you want to check your work, you can plug back in the measures into the original equation to see if a² + b² will equal c², if it does, the answer is correct:
a² + b² = c²
12² + 5² = 13²
144 + 25 = 169
169 = 169 true!
hope this helps! :)