Question

Anyone know the answer

Answer 1

8x16x2=64 So the answer is 64

Answer 2

Yeah... so
Pythagoras theorem
${a}^{2} = {b}^{2} + {c}^{2}$
In your case
${b}^{2} = {8}^{2} + {16}^{2} \\ \sqrt{b}$
So the answer is 64