
Nitin P. answered 05/10/20
Machine Learning Engineer - UC Berkeley CS+Math Grad
We know that the length of AB is 6, the length of CD is 3 (Since C is the midpoint of ED), and the length of BD is 6. AC is the hypotenuse of the right triangle AEC, which has legs of length 6 and 3. Therefore, the length of AC is:
sqrt(62 + 32) = 3 * sqrt(5)
Therefore, the perimeter is 6 + 6 + 3 + 3sqrt(5) = 15 + 3sqrt(5)