I’m in need of help on this please

Answer:
Im going to use the Pythagorean theorem.
a^2+b^2=c^2
Line AB is A, line CB is B, and line AC is C.
4^2+2^2=c^2
4^2=16 and 2^2=4
16+4=20^2=4.5
4.5 shoudl be your answer.
-Seth
Hi!
We will solve this using the Pythagorean theorem, given that length of one side of the square = 1.
AB = 4
BC = 2
AC^2 = AB^2 + BC^2
AC^2 = 4^2 + 2^2
AC^2 = 16 + 4 = 20
AC = square root of 20 = square root of 4 * square root of 5
AC = 2 * square root of 5 or 4.47, the correct answer is C
Hope this helps!