Answer:
Step-by-step explanation:
a^2 = BE*EC
BE = 18
CE = 4 Substitute
a^2 = 18*4 Combine
a^2 = 72 72 can be broken down to 2 * 36.
a^2 = 2 * 36 sqrt(2)*sqrt(36)
a = 6 * sqrt(2)
