Answer:
5 inches
Step-by-step explanation:
Using Pythagoras theorem A² + B² = C² where C² is the squared length of the hypotenuse, here 13². We're looking for the unknown side length B where B² = C² - A². Since A is also known to be 12 inches we get the equation B² = 13² - 12² = 169-144 = 25 => B =√25 =5.
note: while √25 also evaluates to -5, the side length of a triangle cannot be negative and we therefor reject this value.
