The hypotenuse will always be equal to "c." You can put "a" or "b" as 8. This gives us a^2 + 8^2 = 10^2 which simplifies to a^2 + 64 = 100. From there, you simplify (subtract 64, giving you a^2 = 36, and then take the square root of a^2 & 36 to get a = 6 (because 6*6 = 36))