Answer:
Im not sure if this is right but hope it gives u an idea 
Explanation:
so to find a Use the Pythagorean theorem to calculate the hypotenuse from right triangle sides. Take a square root of sum of squares: c = √(a² + b²)
so for number 12 
you do smting like this 
A leg: 17 
B leg: 19
Which would give you 
