Answer:
5cm
Explanation:
To find the missing side we use the hypotenuse theorem.
a^2 + b^2 = c^2
The longest side of the triangle would be c. So substitute the numbers into the variables.
a^2 + 12^2 = 13^2
a^2 = 13^2 - 12^2
a^2 = 169 - 144
a^2= 25
a = √25
a=5
The missing leg's length is 5cm