Since the triangle is a right triangle, and two angles are equal, then there is a property in Trig that states that if the two angles are 45 degrees, then the sides, (or legs) of the triangle are equal in length. Given this....then applying the Pythagorean Thereom:
a^2+b^2=c^2
a^2+b^2 =8^2 -----> a^2+b^2=64
Since the lengths of the sides are equal, then we can rewrite this to say a^2+a^2=64, so 2a^2=64
and so dividing by 2 gives us a^2=32, so a=4sqrt(2)
so the perimeter is 4sqrt(2)+4sqrt(2)+8 = 8sqrt(2)+8
So the correct choice is B
