Question

What’s the length of BD

Answer 1

A = 1/2 pq
let
AC = p
BD = q = 2/3 (p)

so
75 = 1/2(p) (2/3 p)
75 = 1/3 p^2
p^2 = 75 * 3
p^2 = 225
p = 15

so
AC = 15
BD = 2/3(AC) = 2/3 (15) = 10

answer
B. 10 cm