(1) For the three identical squares shown, points A, B and C are vertices, and AB = 2sqrt{5} cm. What is the length of AC, in centimeters? Express your answer in simplest radical form.
Find the side of a square
s^2 + (2s)^2 = 20
5s^2 = 20
s^2 = 4
s = 2
So
AC^2 = s^2 + (3s)^2
AC^2 = 2^2 + 6^2
AC^2 = 4 + 36
AC^2 = 40
AC = √ 40 = 2√10 cm
