Answer:
unmarked angle = 45
side opposite unmarked angle = 5√8
hypotenuse = 20
Explanation:
The unmarked angle is 180 - 90 - 45 = 45
The side opposite this new 45 degree angle is also 5√8
The hypotenuse is
a^2 + b^2 = c^2
a = b = 5√8
a^2 = b^2 = 25*8 = 200
200 + 200 = c^2
c^2 = 400
sqrt(c^2) = sqrt(400)
c = 20