Step-by-step explanation:
<ABD = arcsin 1/5 = 11.5 degree
so <DBC = 90 - 11.5 = 78.5 degree
BD = Square root (5^2 - 1^2) = 4.9
DC = 4.9 * tan 78.5 = 24 (rounded!)
AC = 1 + 24 =25
