From the diagram below, if AD = 5, and DB = 10, what is the length of CD?

Answer:
20
Step-by-step explanation:
According to Euclidian theorem:
h^2 = AD*CD (h is the height, DB in this case)
rewrite the equation by using given values
10^2 = 5*CD find the square value of 10
100 = 5*CD divide both sides by 5
20 = CD