What we need to do first is measure BC and CA.
As we can see BC measures 2, and CA measures 4.
So [tex] 2^{2} [/tex] and [tex] 4^{2} [/tex] give us 20.
And we square root that, and we get: [tex] \sqrt{20} [/tex].
So the answer is: [tex] \sqrt{20} [/tex].
Hope this helped! c:
