The answer is 5 Explanation: We need to use the Pythagorean, a^2 + b^2 = c^2 Where c is the hypotenuse We can fill in spots now 12^2 + b^2 = 13^2 And then we solve 144 + b^2 = 169 Next we get b^2 alone 169-144=25 So we get b^2=25 For the final step you have to find the square root of 25 to get b alone which is 5
